COMPARISON OF FINNED TUBE AND PLATE-FINNED HEAT EXCHANGERS IN WASTE HEAT RECOVERY

Transcription

1 Mario olik Marija Živić Zdravko Virag Antun Barac ttps://doi.org/10.178/tof.4si101 ISSN eissn OMPARISON OF FINNED TUBE AND PLATE-FINNED EAT EXANGERS IN WASTE EAT REOVERY Summary Te use of waste eat recovery devices on mobile units (trucks and sips) is usually limited by te available space and te application of compact eat excangers is recommended for suc purposes. Te performance of te eat excanger is defined by te optimized Rankine cycle (to acieve maximum power) and it depends on te mass flow and temperature of te flue gases and selection of te working fluid in Rankine cycle. An example of selection of te preeater performance (in case of water as te working fluid) is considered ere, werein te several surface types of finned tube and plate-finned eat excangers are used, for wic tere are measured data of te eat transfer coefficient and friction factor. eat excangers are sized according to te criteria of maximum allowed velocity of te flue gases and sapes of te eat excanger frontal area. Te sized eat excangers were compared wit respect to te eat transfer coefficient, te area of te eat excanger surface on te finned side, te volume of te eat excanger and te pressure drop on bot sides. From te comparison of te best plate-finned and te best finned tube eat excangers it is concluded tat in te recommended range of flue gases velocity (from 4 m/s to 6 m/s) te pressure drop at te gas side are similar (in te plate-finned eat excanger it is in te range from 53.5 to 11 Pa and in te finned tube excanger from 53.8 to 14.8 Pa), wile te plate-finned excanger as more tan 50% smaller eat transfer area, compared to te finned tube one. Key words: eat excangers, eat transfer, Minimization of eat excanger volume, Pareto frontier 1. Introduction Burning of fossil fuels releases flue gases wic cause serious problems in te environment, suc as air pollution, global warming, ozone layer depletion and acid rains. In te diesel engine exaust gases tere is a significant amount of energy tat can be utilized and so fuel consumption and environmental pollution can be reduced. Organic Rankine cycle is considered as one of te best tecnologies for te recovery of waste eat from te exaust gases of eavy duty truck diesel engines. Design process of OR system is comprised of eat source selection, candidate fluid selection and termodynamic cycle optimization, [1]. Dolz et al. [] presented a study on te TRANSATIONS OF FAMENA XLII- Special issue 1 (018) 1

2 M. olik, M. Živić, omparison of Finned Tube and Plate-Finned Z. Virag, A. Barac eat Excangers in Waste eat Recovery bottoming Rankine cycle configuration wit all te eat sources wic includes waste energy recovery in a binary cycle. Many studies on waste eat recovery of te diesel engines publised in recent years deal wit te working fluid selection, [3], [4], werein te most often selected fluids are etanol, toluene and water. Invernizzi et al. [5] proposed titanium tetracloride as a new potential working fluid. Some autors used experimental organic Rankine cycle set [6], [7] and termal energy storage [8] to investigate te feasibility of waste-eat-recovery from a diesel engine. Autors establised different optimization models of OR systems. ajabdollai et al. [9] made an optimization of OR for diesel waste recovery in wic tey maximized te termal efficiency and minimized te total annual cost. Su et al. [10] performed parameters optimization wit six indicators, including termal efficiency, exergy destruction factor, turbine size parameter, total exergy destruction rate, turbine volume flow ratio and net power output per unit mass flow rate of exaust. Most of te publised studies are based on te termodynamic approac, not considering te tecnical and operating caracteristics of te system components suc as expanders and eat excangers. One of te few works tat take into account te tecnical caracteristics of te components of te OR system is [11] were te optimal working fluid and operating conditions are selected considering tecnological constraints of te expander, te eat excangers and te feed pump. In several studies an exaust gas eat excanger performances are taken into consideration. Katsanos et al. [1] applied te procedure for te assessment of te optimum Rankine cycle parameters at different operating conditions in wic te eat transfer coefficient and te pressure drop at bot sides of te eat excanger were calculated. Mavridou et al. [13] performed te sizing of a eat excanger for truck applications using five different configurations and compared te conventional and te latest eat transfer enancement tecnologies. Te use of OR installation on mobile units (trucks) is usually limited by available space and for a given eat duty te eat excanger sould be as small as possible in size and weigt, at a reasonable ig pressure drop. For suc purposes te application of compact eat excangers is recommended and teir sizing is of crucial importance. Performance of te eat excanger is defined by te optimized Rankine cycle (to acieve maximum power) and it depends on te mass flow rate and temperature of te flue gases and selection of working fluid in Rankine cycle. An example of selection of te preeater performance (in case of water as te working fluid) is considered ere, werein te several surface types of te finned tube and plate-finned eat excangers are used, for wic measured data of te eat transfer coefficient and friction factor are taken from literature [14]. Te aim of tis study is to compare two types of surfaces in terms of: obtainable overall eat transfer coefficient wit restriction in gas velocity, i.e. te required finned area and required volume. Also, te impact of te sape of te eat excanger frontal area on te maximal linear dimension of te eat excanger and pressure drops in gas and liquid streams is examined.. Matematical model In tis study we consider two types of compact eat excangers (E): finned tube (as depicted in te left panels in Figure 1) and plate-finned (rigt panels in Figure 1). ere we use surface types of te finned tube and plate-finned eat excangers, from te catalogue in te EES (Engineering Equation Solver) program, in wic measured data of te olburn and friction factor in a range of Reynolds number exist. Once te surface type is cosen, we know all te geometric parameters of one eat excanger cell and te frontal area (te area for te gas flow) is A fr = L 1 L 3, were te eigt L 3 is defined by TRANSATIONS OF FAMENA XLII- Special issue 1 (018)

3 omparison of Finned Tube and Plate-Finned eat Excangers in Waste eat Recovery N row sv L3 N p b N p 1 b1 a M. olik, M. Živić, Z. Virag, A. Barac for finned tube E for plate finned E (1) and N s for finned tube E L col Noff ls for plate finned E () were N col and N row is te number of tube columns and rows in te finned tube E, respectively, N p is te number of passages of te liquid stream and N off is te number of strip fins in te plate-finned E. In bot E, L is te lengt for pressure drop in gas stream flow, wile lengt responsible for te pressure drop in liquid stream flow is L1 in te case of platefinned E, and N col L1 in te case of te finned tube E. It is important to note tat in te case of plate-finned E te eigt b of a cannel for te liquid flow can be freely cosen, wile te selection of inner tube diameter di in te case of finned tube E is limited by te outer tube diameter do and (if one wants to use standard tubes) by few variants of te tube wall tickness (ere, we assume di do ). Fig. 1 Left panels: Finned tube eat excanger and corresponding geometric parameters. 3D view of te eat excanger wit definition of lengts L1, L, and L3 (top) and a cross section view (bottom). Rigt panels: Plate-finned eat excanger and corresponding geometric parameters. 3D view of te eat excanger core wit definition of lengts L1, L, and L3 (top) and a cross section view (bottom). TRANSATIONS OF FAMENA XLII- Special issue 1 (018) 3

4 M. olik, M. Živić, omparison of Finned Tube and Plate-Finned Z. Virag, A. Barac eat Excangers in Waste eat Recovery Te problem is to size te eat excanger wen its eat duty q, te eat capacity rate of ot and cold streams ( and ), te inlet temperatures ( T,in and T,in ) and te outlet temperatures ( T,out and T,out ) of bot streams are known from te optimized Rankine cycle. Te eat excanger effectiveness is defined by q T T min,in,in (3) were min is te smaller value from and number of transfer units (NTU) is defined by UA NTU min. In te Effectiveness-NTU metod, te (4) were U is te overall eat transfer coefficient and A is te total gas side eat transfer area (finned area). Depending on te type of eat excanger, tere is a unique relationsip between NTU and [15]. ere, we consider cross-flow gas-to-liquid eat excangers wit one stream unmixed, for wic tis relationsip reads: R 1exp R exp NTU 1 (5) were R is te eat capacity rate ratio min / max. If we neglect te termal resistance in fins and tube/cannel walls, te overall eat transfer coefficient is defined by U (6) were and are te eat transfer coefficients on te cold (liquid) side and ot (gas) side, respectively; is te ratio of te eat transfer surface area at te liquid side to te surface area at te gas side, and 11 fin Afin / A is te extended surface efficiency on te gas side, fin is te fin efficiency defined as fin and tan, (7) A fin is te fin surface area, and A is te total gas side eat transfer surface area. Variable in Equation (7) is defined as: o 0.13mLc Lc r fin k for finned tube E, and (8) o fin 05, b1fin 1 for plate - finned E. (9) k fin ls In above formulas k is material conductivity, L d d e o fin e c and r do d. Special case for finned tube E is if r from Equation (8) ten fin efficiency is defined as 4 TRANSATIONS OF FAMENA XLII- Special issue 1 (018)

5 omparison of Finned Tube and Plate-Finned eat Excangers in Waste eat Recovery M. olik, M. Živić, Z. Virag, A. Barac b am Lc and r ten b ln r fin if a r oefficient b depends on te diameter ratio r and is defined as, else if r coefficient b is b r If r Equation (7) is valid. It is known tat te major part of termal resistance is on te gas side, so it is necessary to focus on enlargement of, wic is defined by c p, jw (10) Pr / 3 were j is te olburn factor, is te average gas density, w is te average gas velocity, c is te gas average specific eat capacity at a constant pressure, and Pr is te Prandtl number. p, In te same time, it is of great interest to reduce pressure drop in te gas stream, and tis pressure drop is proportional to te friction factor f and to te w. Bot j and f decrease wit increase of te Reynolds number ( Re wd /, D is te ydraulic diameter and is te gas viscosity). Tus, to obtain ig (ig U and consequently small A ) te small Re and ig w are needed, wile for small pressure drop te ig Re and small w is required. Since tese two sets of requirements are in contradiction, tere is a need for optimization. Te similar expressions are valid at te liquid-side of te eat excanger, but it is important to note tat te pressure drop in te liquid stream does not significantly influence te efficiency of te Rankine cycle. Tus, it is possible to keep te liquid stream velocity ig, to obtain ig, regardless of te iger pressure drop in liquid stream. In tat sense, te plate-finned E could be better tan finned tube E since te liquid stream velocity can be adjusted arbitrarily by canging of b value. Described matematical models ave been implemented into EES software. Te matematical model of plate-finned eat excanger contains 64 equations (some of tem are specified in tis paper and te rest of tem are auxiliary equations from te EES routines for calculation of olburn and friction factors and geometrical parameters of a given type of eat excanger), wile te model of tube-finned eat excanger contains 63 equations. Wen te number of equations is equal to te number of unknowns te EES software is capable to solve te specified systems of equations regardless te order in wic te equations are specified. 3. Results We consider a preeater in te Rankine cycle wit te following data: mass flow rate of flue gases m 0.49 kg/s in wic te working fluid is water of mass flow rate m kg/s, te gas inlet and outlet temperatures are T,in 33.1 and T 159.5, te inlet and outlet temperatures of water are T,in 5.16 and,out T 19.5 (ot water) at pressure 135 kpa. Te excanger eat duty is q 36.7 kw, at,out and NTU 5. As it is explained above, te main interest ere is to find E wit minimal surface area or volume, and for tis a large is required (i.e. small Re and ig w ). In most of te TRANSATIONS OF FAMENA XLII- Special issue 1 (018) 5

6 M. olik, M. Živić, omparison of Finned Tube and Plate-Finned Z. Virag, A. Barac eat Excangers in Waste eat Recovery existing E te w is about 5 m/s and in some cases it is up to 10 m/s. ere, we will adopt te maximal allowable gas velocity wmax 10 m/s. Eac surface type from te EES catalogue as defined te minimal Reynolds number ( Re min ) at wic te measured values of olburn and friction factor are provided. Te minimal value of te ydraulic diameter of te surface type is defined by Re min and w max in te form D min Re w min max Tere are 3 of te finned tube surface types and 8 of te plate-finned surface types wit te ydraulic diameter greater tan D, and in te following we will sow results for all tree min finned tube surface types and te best four plate-finned surface types listed in Table 1. Table 1 Geometric caracteristics of te considered finned tube and plate-finned surface types ( eat transfer area/total volume; eat transfer area/volume between plates; fin = fin tickness; N f = number of fins per one meter; A fin = fin surface area (including splitter); free-flow area/frontal area) Finned-tube surface type fc_tubes_sf- 87c fc_tubes_sf- 87 fc_tubes_sf- 734 Plate-finned surface type sf_platefin_s1-1194d sf_platefin_s16-118d sf_platefin_s sf_platefin_s18-161t Re min d o d e D fin N f A fin /A s s v Mater. - m /m 3 mm mm mm mm 1/m - - mm mm of fins u Al Al Re min b 1 a D fin N f A fin /A l s b Mater. - m /m 3 mm mm mm mm 1/m - - mm mm of fins Al Al Al Al In te defined matematical model it is possible to freely define tree parameters in te case of plate-finned surface types and two parameters in te case of finned tube surface types (note tat in te first case parameter b can be freely cosen and in te second case d i is uniquely related to kept it to its maximal value d o ). For te first free parameter we selected te (11) w, and at te first we w max. For te second free parameter we used te ratio L1/ L 3 wic defines te sape of te frontal area (square and different rectangles). We ave analyzed five variants of tis ratio: L1/ L 3=1, 1.5, 1/1.5, and 1/. Te tird parameter in te case of plate-finned surface types could be eiter b or te pressure drop at te liquid-side or te. In te considered cases we used b = 0.5 mm (to obtain ig value of at a reasonable ig pressure drop at te liquid side). Figures to 6 sow obtained results (te finned area, overall eat transfer coefficient, eat transfer coefficients at te gas and liquid side, maximal and minimal dimensions among L 1, L, and L 3, number of rows/passages and number of columns/strip fins, and pressure drops at te gas and liquid side) for te seven eat excanger surface types and te five different sapes of te frontal area. 6 TRANSATIONS OF FAMENA XLII- Special issue 1 (018)

7 omparison of Finned Tube and Plate-Finned eat Excangers in Waste eat Recovery M. olik, M. Živić, Z. Virag, A. Barac Fig. alculated finned area (left panel) and te overall eat transfer coefficient (rigt panel) for te seven surfaces and for five cases, for w = 10 m/s and di = do or b = 0.5 mm. Te legend is te same for bot panels. Fig. 3 eat transfer coefficient at te gas side (left panel) and at te liquid side (rigt panel) for te seven surfaces and for five cases, for w = 10 m/s and di = do or b = 0.5 mm. Te legend is te same as in Figure. Fig. 4 olburn and friction factor as a function of Reynolds number for te seven surfaces. TRANSATIONS OF FAMENA XLII- Special issue 1 (018) 7

8 M. olik, M. Živić, Z. Virag, A. Barac omparison of Finned Tube and Plate-Finned eat Excangers in Waste eat Recovery Fig. 5 alculated eat excanger volume (left panel) and te maximal and minimal linear dimension of eat excanger (rigt panel) for te seven surfaces and for five cases, for w = 10 m/s and di = do or b = 0.5 mm. Dots in te rigt panel tat define te maximal dimensions are connected by solid lines and dots denoting minimal dimensions by dased lines. Te legend is te same as in Figures and 4. Fig. 6 Number of rows in finned tube eat excanger or number of passages at liquid side in plate-finned eat excanger (left panel) and number of columns in finned tube eat excanger or number of strip fins in platefinned eat excanger (rigt panel) for te seven surfaces and for five cases, for w = 10 m/s and di = do or b = 0.5 mm. Te legend is te same as in Figures and 4. Fig. 7 Pressure drop in te eat excanger at te gas side (left panel) and at te liquid side (rigt panel) for te seven surfaces and for five cases, for w =10 m/s and di = do or b=0.5 mm. Te legend is te same as in Figures and 4. 8 TRANSATIONS OF FAMENA XLII- Special issue 1 (018)

9 omparison of Finned Tube and Plate-Finned eat Excangers in Waste eat Recovery M. olik, M. Živić, Z. Virag, A. Barac Fig. 8 Left panel: pressure drop in te eat excanger at te gas side as a function of finned area (all points are calculated at gas velocity w = 10 m/s) for te seven surfaces and for five cases. Rigt panel: te same relationsip as in te left panel for te best plate-finned surface and for te best finned tube surface, at different values of te gas velocity. 4. Discussion It is visible in Fig. tat te use of plate-finned surface types results in smaller eat excange area, due to iger overall eat transfer coefficients. All plate-finned surface types are better tan te best finned tube surface types, and te smallest eat excange area is obtained by using surface type sf_plate-fin_s Te overall eat transfer coefficient depends on eat transfer coefficient on bot sides; see Equation (6), wile te gas side is te critical one, since te eat transfer coefficient in gas is usually an order of magnitude smaller tan in liquid. It is visible in Fig. 3 tat plate-finned surfaces sow iger eat transfer coefficient tan finned tube surfaces at bot gas and liquid sides. Te iger in platefinned surface types can be explained by smaller Re min and D (see Table 1) since for given w te smaller D results in smaller Reynolds number and iger olburn factor (see Fig. 4), and consequently in iger, see Equation (10). Te iger in plate-finned surface types can be explained by te fact tat te Reynolds number in te liquid stream (and consequently ) in te case of plate-finned surface types can be kept sufficiently ig, by free selection of parameter b. In plate-finned surface types te overall eat transfer coefficient (and eat transfer area) does not depend on te sape of te frontal area (on te ratio L 1 /L 3 ) and tis is not te case in finned tube surface types. In case of finned tube surface types te Reynolds number in te liquid stream depends on te liquid mass flow troug one tube (total liquid mass flow over te number of tube rows) and te inner tube diameter d i wic cannot be freely cosen. In te case of small liquid mass flow rate, te Reynolds number (and te value of ) can be increased by decreasing te number of rows. It is visible in left panel of Fig. 6 tat in te case L1 L3 (greater widt and smaller eigt of te frontal area) te number of tube rows decreases, and consequently te Reynolds number, (see rigt panel in Fig. 3), U (see rigt panel in Fig. ), and pressure drop in liquid stream (see rigt panel in Fig. 7) increase, wile A (left panel in Fig. ) and number of columns decrease (see rigt panel in Fig. 6). Te case L / 1 L 3 (smaller widt and greater eigt of te frontal TRANSATIONS OF FAMENA XLII- Special issue 1 (018) 9

10 M. olik, M. Živić, omparison of Finned Tube and Plate-Finned Z. Virag, A. Barac eat Excangers in Waste eat Recovery area) as te opposite effect, and tis option can be useful wen te liquid mass flow rate and pressure drop in liquid stream are too ig and te increased number of tube rows is required. Fig. 5 sows tat te volume of te plate-finned eat excangers is significantly smaller tan te volume of te finned tube eat excangers. Also, in cases of plate-finned eat excangers, te volume does not depend on te sape of te frontal area. In tese eat excangers, te minimal dimension is L (in all cases it is smaller tan L 1 and L 3 ), wile te maximal dimension rises wit deviation of L1/ L 3 from one (te maximal dimension is te smallest for L1/ L 3=1). In cases of finned tube eat excangers, te sape of frontal area as a great impact on te volume and maximal dimension of eat excanger. Te volume is decreased by decreasing L 3 and increasing L 1 (tat is wy te number of rows is decreased, te Reynolds number in te liquid stream is increased and consequently and U are increased, and A is decreased). Fig. 7 sows pressure drops in gas and liquid streams, and it is visible tat te pressure drop in gas stream (wic sould be kept very small) is smaller in te case of plate-finned surface types. Tis pressure drop is proportional to te friction factor, wic is greater in plate-finned surface types (see rigt panel in Fig. 4), and lengt L. In plate-finned eat excangers L corresponds to L min, and in finned tube eat excangers to L max (compare L min and L max in te rigt panel of Fig. 5), and tat is wy te pressure drop is smaller in platefinned eat excangers. Similarly, in te liquid stream, te friction factor and velocity are greater in te case of plate-finned eat excangers, but te lengt for te pressure drop is smaller (it is L 1 for plate-finned surface types and NcolL 1 ) terefore te pressure drop in liquid stream of plate-finned eat excanger does not need to be greater tan in finned tube eat excangers. For making te decision wic variant of eat excanger is te best in cases of restricted volume or maximal allowable dimension, it can be useful to see a diagram sowing pressure drop in te gas stream (te most influential parameter on te efficiency of te Rankine process) as a function of te volume/maximal dimension or eat excanger surface area. In suc a diagram left panel in Fig. 8 sows all considered variants of eat excanger, and in te rigt panel te Pareto frontier for te best one plate-finned and te best one finned tube surface type is sown. Tis frontier is obtained by varying te gas velocity w. At a smaller velocity te pressure drop is smaller, but te surface area is larger. Te Pareto frontier contains solutions wic sow (wen compared to oter solutions) eiter a smaller pressure drop or surface area. From suc diagram a designer can coose te best variant according to is preferences. Te plate-finned eat excanger is better coice since it requires smaller finned area, for te similar pressure drop at gas side. For w =4 m/s, te pressure drops in plate finned and finned tube eat excangers are 53.5 and 53.8 Pa, respectively and corresponding finned surfaces are and 3.85 m. At w =6 m/s te pressure drops are and 14.8 Pa and required finned surfaces are 9.09 and 0.99 m. 10 TRANSATIONS OF FAMENA XLII- Special issue 1 (018)

11 omparison of Finned Tube and Plate-Finned eat Excangers in Waste eat Recovery M. olik, M. Živić, Z. Virag, A. Barac 5. onclusion Te matematical model for sizing of te plate-finned and finned tube eat excangers, as well as te procedure for selecting te best variant of te eat excanger is defined. Te procedure is applied to a preeater wit known eat duty and required efficiency. Seven surface types and five sapes of frontal area are analyzed and te best plate-finned and te finned tube eat excangers are compared in terms of pressure drop at gas side and required finned area. In te recommended range of te flue gases velocity (from 4 m/s to 6 m/s) te pressure drop at te gas side are similar (in te plate-finned eat excanger it is in te range from 53.5 to 11 Pa and in te finned tube excanger from 53.8 to 14.8 Pa), wile te platefinned excanger as more tan 50 % smaller eat transfer area, compared to te finned tube one (at w =4 m/s, te finned area in te plate-finned and finned tube excangers are and 3.85 m, respectively, and at at w =6 m/s tese areas are 9.09 and 0.99 m ). Tis advantage can be explained by te fact tat te olburn factor (and te eat transfer coefficient) at te gas side is iger in te case of finned-plate eat excanger tan in finned tube surfaces. Also, te eat transfer coefficient at te liquid side is iger in te case of plate-finned surfaces, since te Reynolds number at liquid side can be freely adjusted by free selection of b (wic is not te case in finned tube surfaces, were te inner tube diameter is strictly related to outer diameter). In te case of plate-finned surface types te eat excanger volume, its minimal dimension and overall eat transfer coefficient are not sensitive to te cange of te sape of te eat excanger frontal area, and tis is additional advantage in te case of limited space for placement of eat excanger. REFERENES [1] Amicabile, S., Lee, J. and Kum, D., A compreensive design metodology of organic Rankine cycles for te waste eat recovery of automotive eavy-duty diesel engines, Applied Termal Engineering, Vol. 87, pp , 015. ttps://doi.org/ /j.appltermaleng [] Dolz, V., Novella, R., García, A. and Sáncez, J., D Diesel engine equipped wit a bottoming Rankine cycle as a waste eat recovery system. Part 1: Study and analysis of te waste eat energy, Applied Termal Engineering, Vol. 36, pp , 01. ttps://doi.org/ /j.appltermaleng [3] Panesar, A. S., Morgan, R. E., Micé, N. D. D. and eikal, M. R., Working fluid selection for a subcritical bottoming cycle applied to a ig exaust gas recirculation engine, Energy, Vol. 60, pp , 013. ttps://doi.org/ /j.energy [4] Kölsc, B. and Radulovic, J., Utilisation of diesel engine waste eat by Organic Rankine ycle, Applied Termal Engineering, Vol. 78, pp , 015. ttps://doi.org/ /j.appltermaleng [5] Invernizzi,. M., Iora, P., Bonalumi, D., Macci, E., Roberto, R. and aldera, M., Titanium tetracloride as novel working fluid for ig temperature Rankine ycles: Termodynamic analysis and experimental assessment of te termal stability, Applied Termal Engineering, Vol. 107, pp. 1 7, 016. ttps://doi.org/ /j.appltermaleng [6] Yu, G., Gequn, S., ua, aiqiao, W. and Lina, L., Simulation and termodynamic analysis of a bottoming Organic Rankine ycle (OR) of diesel engine (DE), Energy, Vol. 51, pp , 013. ttps://doi.org/ /j.energy [7] Zang, Y., Xia, W. Y. G., Ma,., Ji, W., Liu, S., Yang, K. and Yang, F., Development and experimental study on organic Rankine cycle system wit single-screw expander for waste eat recovery from exaust of diesel engine, Energy, vol. 77, pp , 014. ttps://doi.org/ /j.energy [8] Wilson, J. M. R., Sing, Abisek K., Sing, Abinay K., Ganapaty S.L.R., Waste eat recovery from diesel engine using custom designed eat excanger and termal storage system wit nanoenanced pase cange material, Termal Science 017 Volume 1, Issue 1 Part B, pp ttps://doi.org/10.98/tsi w TRANSATIONS OF FAMENA XLII- Special issue 1 (018) 11

12 M. olik, M. Živić, omparison of Finned Tube and Plate-Finned Z. Virag, A. Barac eat Excangers in Waste eat Recovery [9] ajabdollai, Z., ajabdollai, F., Terani, M. and ajabdollai,., Termo-economic environmental optimization of Organic Rankine ycle for diesel waste eat recovery, Energy, vol. 63, pp , 013. ttps://doi.org/ /j.energy [10] Su, G., Li, X., Tian,., Liang, X., Wei,. and Wang, X., Alkanes as working fluids for igtemperature exaust eat recovery of diesel engine using organic Rankine cycle, Applied Energy, Vol. 119, pp , 014. ttps://doi.org/ /j.apenergy [11] Maraver, D., Royo, J., Lemort, V. and Quoilin, S., Systematic optimization of subcritical and transcritical organic Rankine cycles (ORs) constrained by tecnical parameters in multiple applications, Applied Energy, Vol. 117, pp. 11-9, 014. ttps://doi.org/ /j.apenergy [1] Katsanos,. O., ountalas, D. T. and Pariotis, E. G., Termodynamic analysis of a Rankine cycle applied on a diesel truck engine using steam and organic medium, Energy onversion and Management, Vol. 60, pp , 01. ttps://doi.org/ /j.enconman [13] Mavridou, S., Mavropoulos, G.., Bouris, D., ountalas, D. T. and Bergeles, G., omparative design study of a diesel exaust gas eat excanger for truck applications wit conventional and state of te art eat transfer enancements, Applied Termal Engineering, Vol. 30, pp , 010. ttps://doi.org/ /j.appltermaleng [14] Kays, W. M. and London, A. L., ompact eat Excanger - tird edition, Krieger Publising ompany, Florida, USA, [15] Sa, R. K. and Sekulić, D. P., Fundamentals of eat excanger design, Jon Wiley & Sons, Inc., New Jersey, USA, 003. ttps://doi.org/10.100/ Submitted: Accepted: Mario olik, mag. ing. mec. Prof. dr. sc. Marija Živić Mecanical Engineering Faculty in Slavonski Brod, J.J. Strossmayer University of Osijek, Trg I. B. Mažuranić, Slavonski Brod, roatia Prof. dr. sc. Zdravko Virag Faculty of Mecanical Engineering and Naval Aritecture, University of Zagreb, I. Lučića 5, Zagreb, roatia Antun Barac, mag. ing. mec. Mecanical Engineering Faculty in Slavonski Brod, J.J. Strossmayer University of Osijek, Trg I. B. Mažuranić, Slavonski Brod, roatia 1 TRANSATIONS OF FAMENA XLII- Special issue 1 (018)