WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 1 27/01/2009 Contents Contents ................................................. ......... ......................................... ........................... ....................... ................ 1 Thermal and hydraulic design of shell and tube heat exchangers .......................................... .............. .............. 2 Processing of the pipe determine the piezometric level data ............................................ .................. ................................ 4 Properties of water ............................................... .............. .................................... ................................ .................. .......... 6 Properties of water ............................................... .............. .................................... ................................ .................. .......... 7 Heat transfer during flow through pipes .............................................................. ................................ .................... 8 Heat transfer in the exterior of tubular heat exchangers with baffles ........................................... ....... 11 Tube vibration analysis .............................................. ............ .................................................................... .......... 14 Tube-side pressure loss in tubular heat exchangers ......................................................... ....................................... .... 15 Pressure loss in the exterior of tubular heat exchangers with and without internals ......................................... ............. 17 CAD program for shell and tube heat exchanger .......................................................... ...................................... ................... 19 Real log.Temperaturdifferenz and temperature distribution for the cell model ......................................... .................... ... 20 MS EXCEL specification
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WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 1 27/01/2009 Contents Contents ................................................. .................................................................................................... ................ 1 Thermal and hydraulic design of shell and tube heat exchangers .......................................... ............................ 2 Processing of the pipe determine the piezometric level data ............................................ .................................................. 4 Properties of water ............................................... .................................................................................................... .......... 6 Properties of water ............................................... .................................................................................................... .......... 7 Heat transfer during flow through pipes .............................................................................................. .................... 8 Heat transfer in the exterior of tubular heat exchangers with baffles ........................................... ....... 11 Tube vibration analysis .............................................. .......................................................................................... 14 Tube-side pressure loss in tubular heat exchangers ................................................................................................ .... 15 Pressure loss in the exterior of tubular heat exchangers with and without internals ......................................... ............. 17 CAD program for shell and tube heat exchanger ................................................................................................ ................... 19 Real log.Temperaturdifferenz and temperature distribution for the cell model ......................................... ....................... 20 MS EXCEL specification sheet ................................................................................................. .............................................. 21 CAD created with WTSC .............................................. .................................................................................................... ......... 22 Piezometric created with SPIE ................................................................................................ .................................................. 23 Piezometric 3D with Alibre Design from SPIE ............................................................................................. .............................. 24 WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach Engineering 2 1/27/2009 Tube side: shell side: Medium: water medium: water M_i mass flow of 72000 kg / h mass flow M_A 90222 kg / h Flow V_i 73.53 m³ / h Airflow V_a 90.6 m³ / h Standard Vol.strom V_i m ³ / h standard Vol.strom V_a m ³ / h Pressure (abs) P_i 3 bar pressure (abs) P_A bar 4 Eintrittstemp. The 80 ° C _i Eintrittstemp. The _a 20 ° C Outlet temp. Yes _i 55 ° C outlet temp. Yes _a 40 ° C
Actual Actual Outlet temp. Ji _a 53.94 ° C outlet temp. Yes _a 40.85 ° C Midweek. Temp Jm _i 67.5 ° C mean. Jm _a Temp 30 ° C Density r _ i 979.2 kg / m³ density r _ a 995.9 kg / m³ Spec Wärmek. cp_i 4188 J / (kg * K) Wärmek Spec. cp_a 4178 J / (kg * K) Therm. l _i 0.6575 W / (mK) Therm. l _a 0.6152 W / (mK) Viscosity h _ i 0.4179 m Pa s Viscosity h _ a 0.7976 m Pa s Fouling f_i 0 m ² * K / W fouling F_A 0 m ² * K / W Heat flow q_i k -2094 W heat flow Q_A 2094 k W Heat loss Q_v_a 0 k W Geometry: Title of design: Mounting: Horizontal Segmentumlenkbleche Smooth tubes smooth tubes Mantelaußendurchm. Since m 406.4 m 8.8 m Sat sheath thickness m Mantelinnendurchm. Tues m 388.8 m Bundle-sheath distance 13.79 m min-m intervals. Bundle-sheath 12 m m Pipe outside diameter as 25 mm R ear inside diameter D 21 mm Tube pitch (horizontal) 32 mm sq R ear distribution (longitudinal) sl 27.71 mm Pitch angle 60 ° F G asse wide b 49 m m . Abst 190 mm Number of baffles Umlenkbl \ Gang 19 - Dist RB-1.Umlenkblech 290 m m diameter. Baffles 385.8 m m 25.8 mm hole in the baffle size of the window 20% Sealing strip pairs 0 - Thermal conductivity of the pipe material l 15 W / (mK) Total Fouling resistance R 0 m ² * K / W Shell Side Tube Side Number of passes 2 - 1 - Number of series-connected heat exchanger 1 - - Thermal and hydraulic design of shell and tube heat exchangers WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach Process Engineering 3 1/27/2009 Rating: executed necessary A Übertragerfläche 23:49 m 25.13 m ² ² Aa Bundle length l la 3,739 m 4 m Results: Number of tubes R 80 - Heat transfer coefficient (s) a_ i 9229 W / (m² K) Heat transfer coefficient (outside) a_ a 8656 W / (m² K) Heat transfer coefficient k 2565 W / (m² K) Log Mean. Temperature difference (LMTD) DJ K 37.44 FN (correction factor for LMTD) FN 0.9279 - Tube side: shell side: Link Speed. in the tube 1474 m / s Link Speed in the sheath 1023 m / s Speed window, 2.048 m / s Pressure drop Dp i 0.1795 b ar a pressure loss Dp 0.5317 b ar Wall temperature of 55.09 ° C i Jw Jw a wall temperature 41.11 ° C Dia. Lop a 131.7 m m diam. Lop a 159.3 m m Dia. Tail of 131.7 m m diam. Tail of 159.3 m m Geschwind. Lop a 1,499 m / s speed. Lop a 1,263 m / s Geschwind. Tail of 1,499 m / s speed. Tail of 1,263 m / s
r * V ² inlet nozzle 1588 k g / (m * s ²) Equations: Heat balance for the tube side: Q_i = m_i · cp_i * (Yes _i - The _i) + m_i · x_i v_i ° DH 4188 = 20 × (55 - 80) + 20 × 1 × 0 K = -2094 W Heat balance for the shell side: Q_A = M_A · cp_a * (Yes _a - The _a) + M_A · x_a ° DH v_a = 6.25 · 4178 (40-20) + 6.25 × 1 • 0 K = 2094 W Heat balance: Q_i = - (Q_A - Q_v) -2093942 = - (2093942-0) Heat transfer coefficient k: 1 1 ln da da (da / di) 1 da = + Fi · + + + fa, f = fi · + fa k a_ i di 2 / liter a_ A di 1 0.025 0 025 l s (0.025 / 0.021) = + 0 ° + 9229 0.021 2 × 15 1 + + 0 8656 k = 2565 W / (m² K) Q = k * A * DJ · FN = · 2565 23:49 · · 37.44 -2094 0.9279 = k W WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach Process Engineering 4 27/01/2009 Title of design: Baffle type: Segmentumlenkbleche Effective pipe length l 3,739 m Global surface A 23:49 m ² Design = D; Rating / Simulation = R <R> Number of heat exchangers in series 1 - Executed tube length 4000 m la m Since the outside cladding diameter 406.4 m m Coat the inside diameter D m 388.8 m Beam diameter Db m 361.2 m Minimum distance between bundle sheath and 12 m m Dm Distance between bundle sheath and D m 13.79 m Tube outside diameter as 25 m m Tube inner diameter d 21 m m Distribution across the flow direction of 32 m sq m Distribution along the flow direction 27.71 mm sl Pitch angle 60 ° F Diameter of the baffle Dl 385.8 m m Height of the window into the baffles H 77.16 mm Height of the window in% of the diameter 20% Position: aligned offset = f / = v <V> Window height adjust> J / N < Arrangement: at the central tube = 0 <0> - 1/2-Teilung to offset = 1 Number of tube side passes 2 - Number of shell-side passageways 1 -
Bundle-type <1> - Tube lane width (horizontal) 49 m m Tube lane width (vertical) 49 m m Outside diameter of the soil, since m m Reference diameter Dt m m Number of bolts on the pitch - Rotation angle of the pitch circle ° for drilling pattern Total number of tubes n 80 - Number of tubes in the windows nF 19 - Number of tubes in cross flow zone nS 61 - Number of border pipes required / available RR / 50 Number of tube rows in the window NRF 1.5 - Number of tube rows in the cross-flow zone nW 7 - Number of tube rows in the end zone NWE 8.5 - Shortest connecting path in the middle of Le 129.4 mm Shortest connecting path between the tube and pipe e 7 mm Shortest connecting path between the tube and sheath e1 33.22 mm Number of connection lines nV 9 - Mean distance of the edge tubes bundle center rh 139.2 mm Tubes per pass: Passage no. 1 2 3 4 5 6 7 8 Number of tubes 40 40 0 0 0 0 0 0 - Processing of the pipe determine the piezometric level data WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 5 27/01/2009 Baffles: Number of baffles N 19 - Spacing of the baffles 190 m m S1 Distance between the bottom - 290 m m baffle S2 Baffle hole diameter in 25.8 m m Outlet: tube side shell side Inner diameter of the inlet pipe 131.7 mm 159.3 mm Inner diameter of the outlet pipe 131.7 mm 159.3 mm Design criteria: Maximum bundle length m m Maximum ratio of l to Db - Minimum ratio of l to Db - WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 6 27/01/2009 Properties of Water and Steam Condition 1: Condition 2: Calculation for <N> <N> Saturation Y / N J1 J2 temperature 67.5 ° C 55.08 ° C Pressure p 1 3 b a r p 2 300 000 P a Properties of water and superheated steam: Condition 1 Condition 2 Liquid Liquid Specific enthalpy h 282 771 J / kg h 230 830 J / kg Specific internal energy u 282 464 J / kg u 230 525 J / kg
Specific entropy s 924.2 J / (kg * K) s 768.9 J / (kg * K) Real gas factor Z 0.001949 - 0.002009 Z - Spec ISOB. Heat capacity. c p 4186 J / (kg * K) C p 4180 J / (kg * K) Spec Isoch. Heat capacity. c v 3935 J / (kg * K) c v 3998 J / (kg * K) Specific volume v 0.001021 m³ / kg v 0.001014 m³ / kg K density r 979.3 g / m³ k r 985.8 g / m³ Dynamic viscosity h 0.4179 m sh 0503 m Pa Pa-s Kinematic viscosity n 4.267E-7 m / sn 5.103E-7 m / s Thermal conductivity l 0.6576 W / (mK) l 0646 W / (mK) Prandtl number Pr 2.66 - Press 3255 - Thermal diffusivity a 1.604E-7 m / sa 1.568E-7 m / s Surface tension s 64.92 N m / ms 67.08 m N / m Therm. Expansion coeff. b 0.000569 1 / K b 0.000492 1 / K Isentropic exponent k 7918 - k 7901 - Speed of sound w 1557 m / s w 1551 m / s Dielectric constant e 64.52 - 68.31 e - Critical state variables: T c = 647.096 K (= 373.946 ° C) 0.01 ° C £ J £ 2000 ° C P c = 220.64 bar; rc = 322 kg / m 3 £ p £ 0.00612 bar 500 bar Properties of water WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 7 27/01/2009 Properties of Water and Steam Condition 1: Condition 2: Calculation for <N> <N> Saturation Y / N J1 J2 temperature 30 ° C 41.11 ° C Pressure p 1 4 b a r p 2 400 000 P a Properties of water and superheated steam: Condition 1 Condition 2 Liquid Liquid Specific enthalpy h 126 106 J / kg h 172 511 J / kg Specific internal energy u 125 704 J / kg u 172 108 J / kg Specific entropy s 436.7 J / (kg * K) s 587 J / (kg * K) Real gas factor Z 0.002871 - 0.00278 Z - Spec ISOB. Heat capacity. c p 4179 J / (kg * K) C p 4178 J / (kg * K) Spec Isoch. Heat capacity. c v 4117 J / (kg * K) c v 4066 J / (kg * K) Specific volume v 0.001004 m³ / kg v 0.001008 m³ / kg K density r 995.8 g / m³ k r 991.9 g / m³ Dynamic viscosity h 0.7972 0.6394 mPa sh mPa.s Kinematic viscosity n 8.006E-7 m / sn 6.446E-7 m / s Thermal conductivity l 0.6152 W / (mK) l 0.6302 W / (mK) Prandtl number Pr 5416 - Press 4239 - Thermal diffusivity a 1.478E-7 m / sa 1.521E-7 m / s Surface tension s 71.19 N m / ms 69.42 m N / m Therm. Expansion coeff. b 0.000303 1 / K b 0.000393 1 / K Isentropic exponent k 5687 - k 5833 - Speed of sound w 1511 m / s w 1534 m / s Dielectric constant e 76.65 - 72.84 e - Critical state variables: T c = 647.096 K (= 373.946 ° C) 0.01 ° C £ J £ 2000 ° C P c = 220.64 bar; rc = 322 kg / m 3 £ p £ 0.00612 bar 500 bar Properties of water
WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 8 27/01/2009 Constant wall temperature Circular pipes Inlet temperature J_ e ° C Outlet temperature J_ a ° C Mean Temperature J_ m ° C Dynamic viscosity of the fluid h 0.4179 mPa s Density of the fluid k r 979.2 g / m³ Thermal conductivity of the fluid l 0.6575 W / (mK) Specific heat capacity of fluid cp 4188 J / (kg * K) Prandtl number Pr 2661 - Prandtl number at wall temperature PrW 3255 - Fluid: liquid <0> or gaseous form <1> <0> Circular tubes = 0 <0> Non-circular pipes = 1 Tube length L 4000 m m Inner diameter of the tube tue 21 m m Cross-sectional area of the tube f 0.000346 m² Circumference of the pipe u m 65.97 m ⇒ hydraulic diameter dh = 21 m m Total mass flow k g Mg / s Total volume flow Vg m ³ / h Number of parallel tubes through which flows Z - ⇒ mass flow per tube M k = 0.5 g / s ⇒ flow velocity w = 1474 m / s ⇒ Reynolds number Re = 72 550 - Result: Q = Mg · cp * (a J_ - J_ e) = k W Results: Constant wall temperature Nu / liter 294.7 · 0.6575 ⇒ a = = = 9229 W / (m² K) ie 0021 w degrees ° r 1474 0021 · · 979.2 Re = = = 72 550 h / 1000 0.4179 / 1000 Nu_m_ J = (L amina r-developed flow Re <2300) [6] Nu_m_ J = (L amina re starting flow Re <2300) [12] Nu_m_T = 301.3 (T urbulente flow Re> 10000) [26] Nu_m = (t berga ngsbereich £ 2,300 £ 10,000 Re) [29] Correction factor K: 00:11 Liquids: K = (Pr / PrW) = 0.9781 n Gas: K = (T / TW) = f ü r n = 0 Nu_m Nu = (_ J, T) * K = 294.7 [40.41] Heat transfer: Q = a * A * DJ l og = 9 229 ° · ⇒ wall temperature J_ w = 55.09 ° C - Heat transfer during flow through pipes WTS example expression Thermal and hydraulic design of shell and tube heat exchangers
Nu_m_L_2300 = 5539 [31] 2 / 3 (0.0308 / 8) · 10000 · ie Pr Nu_m_T_10000 × 1 = + = 2 / 3 l 1 + 12.7 ° 0.0308 / 8 × (Pr -1) [37] Nu_m_T_10000 = 61.15 Re - 2300 72550 - 2 300 g = = = [30] 10000 - 2300 10000 - 2300 Nu_m = (1 - g) · Nu_m_L_2300 Nu_m_T_10000 + g / = [29] · WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 11 01/27/2009 Pipe arrangement: Puts Inner diameter of the casing D i m 388.8 m Diameter of the deflection plate D 1 m 385.8 m Diameter of the tube bundle D B m 361.2 m Height of the section from the baffle H 77.16 mm Spacing of the baffles 190 m S m Number of tubes including pre-n 80 - existing reactive and insulating pipes Number of tubes in the upper and lower n F 19 - Metal cutting (windows) Outer diameter of the tubes d a 25 m m Diameter of the holes for the tubes d B 25.8 mm in the baffle Tube pattern across the flow direction s 1 32 mm Tube spacing in the direction of flow s 2 m 27.71 m Number of sealing strip pairs n S 0 - Main resistance in the cross-flow zone n W 7 - Number of connection lines n V 9 - Number of mantels. Times (for 1 or 2) ND 1 - Lane width (for ND = 2) b 49 m m · Volume V 90.6 m³ / h JE inlet temperature 20 ° C YES outlet temperature 40 ° C Average wall temperature of 41.11 ° C JW Fluid: liquid <0> gas <1> <0> Prandtl number Pr 5416 - Prandtl number at wall temperature, Pr W 4243 - Kinematic viscosity of the fluid n 8.009E-7 m / s Thermal conductivity of the fluid l 0.6152 W / (mK) Results: W = G ⋅ f f f f B length = 1093 · 0.8554 0.8068 = 0.7545 · Nu 0, AW = f heat Nu 0, Bundle = 0.7545 · 712.1 = 537.2 Nu 0, Re / liter 537.2 · 0.6152 a = * K = · 1063 = 8947 p / 2 * d a p / 2 × 0025 - Heat transfer in the exterior of tubular heat exchangers with
Baffles WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 12 01/27/2009 Calculation of Nu 0, bundle: a = s 1 / da = 1.28 b = s2/da Re = 1,109 y, 1 = 43 225 y = 1 - p / 4 (for b ≥ 1) y = 1 - p / 4ab (for b <1) y = 0.3864 3 Nu 1, lam = 0664 · Re y, 1 × Pr 3 242.4 = 0 .664 43 225 · · 5416 0037 · Re y, 1 0.8 · Pr Nu 1, turb = 1 + 2443 · Re y, 1 -0.1 * (Pr (2 / 3) - 1) 43 225 0037 · 0th 8 × 5416 372.4 = 1 + 43 225 2443 · -0.1 * (5416 (2 / 3) - 1) 2 2 Nu Nu 0.3 + 1.0 = 1, nu 1 + lam turb, 444.7 = 0 .3 + 242.4 2 + 372.4 2 Nu 0, Nu bundle = f A * 1.0 = 1601 = 712.1 444.7 · 2 f A = 1 + = 1601 3 × b Calculation of f G: R G = F n / (n / ND) = 19 / (80 / 1) = 0 .2375 f G = 1 - R + G * R 0524 G 12:32 1093 = 1 - 0.2375 + 0.2375 0524 · 0th 32 - WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 13 01/27/2009 Calculation of f L: e = 0.007 e 1 = 0.03322 L E (e, e 1) = 0.1294 n = 80 n F = 19 d B = 0.0258 d a = 0.025 n n F p (d B 2 - d a 2) A SRU = - · = 0.00225 ND 2 4 g = 2 arccos (1 - 2 H / D 1) = 2 arccos (1 - 2 * 0.07716 / 0.3858) = 106.3 p (360 - g) SMU = A * (D i 2 - D 1 2) · 4 360 ° ND 0.001286 = p / 4 × (0.3888 2 - 0.3858 2) * (360 - 106.3) / (360 × 1) A SG + A = A SRU SMU = 0.00225 + 0.001286 = 0.003537 A E = S × L E = 0.19 · 0.1294 = 0.02459 R L = SG A / A E = 0.003537 / 0.02459 = 0.1438
A SRU SRU A f L = 0.4 + 1 - 0.4 exp (-1.5 * R L) A SG A SG 0.00225 0.00225 0.8554 = 0.4 + 1 - 0.4 exp (-1.5 ° 0.1438) 0.003537 0.003537 Calculation of f B: AB = S * (D i - DB - e) = 0.003911 e <(i D - DB) AB = 0 otherwise R B = A B / A E = 0.003911 / 0.02459 = 0159 3 f B = exp - ß · RB 1-2 × n S / n for n W n S £ W / 2 3 0.8068 = exp - ß · 0159 1 - 2 ° 0 / 7 f B = 1 for n S> n W / 2 WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach Engineering 14 01/27/2009 General approach Outer diameter of the tubes as 25 m m Pipe wall thickness s 2 m m Inner diameter of the tubes tue 21 m m Tube pattern across the flow direction of 32 m sq m Tube spacing along the flow direction 27.71 mm sl Transverse pitch ratio sq / da 1.28 - Longitudinal pitch ratio sl / since 1109 - Cross-sectional area of the tubes A 144.4 m m ² Moment of inertia of the tubes 9611 J m m ^ 4 Young's modulus of the tube material E 200000 N / mm ² Effective density of the tube material r 7850 kg / m³ Storage of pipes: 1 Selected storage of the pipes: fixed - articulated Correction factor for the storage of the tubes C 3.93 - Correction factor for additional forces Cf 1 - Arrangement of the pipes (1-3) 1 Selected arrangement: Staggered smooth pipes ® Strouhal number of the bundle Sr 0.2219 - Running span of the tubes L 290 mm 480 mm Velocity in the narrowest cross-section we 1,263 m / s 1023 m / s Natural frequency of the tubes fR 1203 1 / s 439.3 1 / s Safety factor S 1.5 - Allowable excitation frequency fz = fR / S fz 802.3 1 / s 292.9 1 / s Excitation frequency of the flow ferr 11:21 1 / 9081 s 1 / s Vibration risk if ferr> fz Equations di = da - 2 * s = 25 - 2 * 2 = 21 m m A = p / 4 * (because 2 - di 2) = p / 4 × (25 2 - 21 2) = 144.4 mm ² J = p / 64 * (as 4 - di 4) = p / 64 ° (25 4-21 4) = 9611 mm ^ 4 10 6 C 2 E * J fR = · · Û ° CF 2 * r * A p L 10 6 3.93 2 200000 9611 · 1203 = · · 1 2 x 290 p 7850 · 144.4 fz = fR / S u = 1203 802.3 / 1.5
SSt · We · 0.2219 1263 ferr = Û = 11:21 da/1000 25 / 1 0 0 0 Tube vibration analysis WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 15 01/27/2009 Material Properties fluid wall Inlet temperature of 80 ° C YES outlet temperature 55 ° C Average temperature 67.5 ° C 55.09 J ° C Pressure on entry P E 300 000 Pa r the fluid density 979.2 kg / m³ 980.2 kg / m³ Specific heat capacity 4188 J / (kg * K) Thermal conductivity of the fluid l 0.6575 W / (mK) Dynamic viscosity of the fluid h 0.4179 m Pa s 0503 m Pa-s Fluid: liquid = 0, gas = 1 0 G acceleration due to gravity 9.81 m / s ² Type (straight pipe = 1, U-tube = 2) 1 Inside diameter inlet pipe DTNI 131.7 m m Inner diameter outlet DTNO 131.7 m m Number of tube side passes NTP 2 - Number of tubes per pass, N 40 - Length of the tubes per pass, L 4000 m m Inner diameter of the tubes DI 21 m m Outer diameter of the tubes DO 25 m m Pipe wall thickness t = 2 m m Mass flow W 20 k g / s Average velocity in the inlet nozzle Vn E = 1.499 m / s Average velocity in the outlet pipe Vn A = 1.499 m / s Average velocity in the pipe Vt = 1474 m / s Reynolds number Re = 72 537 - Prandtl number Pr = 2661 - Grashof number Gr = 498 913 - Pressure loss coefficient Ke = 3.2 - Friction coefficient of x i s = 0.0059 - Correction factor for the viscosity of F = 1029 - Correction factor for the convection y = 1 - Coefficient of friction (xis × F × y) x = 0.00607 - Pressure loss in the inlet pipe DP n E = 989.8 Pa Pressure loss in the outlet pipe DP n A = 989.8 Pa Pressure loss for inlet, outlet and diversion DP e P a = 3404 Pressure drop due to friction DP t = 9839 Pa Pollution factor Ft = 1277 - Total pressure drop (DP s DP + e + t ft * DP) DP = 17 946 Pa - Tube-side pressure loss in tubular heat exchangers WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process engineering 16 01/27/2009 Equations t = 1 / 2 * (DO - DI) 0002 Û = 1 / 2 * (0025-0021) 1273 × W 1273 × 20
Vn E = 1499 = Û DTNI 2 * r 2 * 0.1317 979.2 1273 × W 1273 × 20 V n A = 1499 = Û DTNO 2 * r 2 * 0.1317 979.2 1273 × W 1273 × 20 Vt = 1474 = Û DI 2 × N × r 2 × 0021 40 × 979.2 Pre-drying DI * R 1474 0021 · · 979.2 Re = 72 537 = Û h / 1000 0.000418 Pr = h / 1000 ° CP / Û l = 0.000418 · 2661 4188 / 0.6575 DI 3 g / r - r W Gr = · (H / 1000 / r) ² r · 9.81 0021 3 979.2 - 980.2 498 913 = · (0.000418 / 979.2) 979.2 ² Pressure loss coefficient for: Straight pipes: a through-Ke = 0.9 NTP = 2 multiple passes Ke = 1.6 · NTP U-tubes: two passes Ke = 0.9 four or more passes Ke = 0.8 · NTP Ke = 3.2 x = x i s i s (Re) = 0.0059 x = i s (72 537) F = F (Re, h / h W) = 1029 = F (72 537, 0.8307) y = y (Re, Pr magnitude h / h W) = 1 = y (72 537, 1102978) DP n E r = Vn E * E ² / 2224 = 989.8 = 979.2 · ² 1499 / 2224 DP n A = r A * A Vn ² / 2224 = 989.8 = 979.2 · ² 1499 / 2224 DP e = Ke • R • Vt ² / 2.0 = 3404 = 3.2 · 979.2 · 1474 ² / 2.0 X-Vt ² · NTP * L DP t = 2 * x * DI 979.2 · 1474 ² × 2 × 4 9839 = 2 × 0.00607 · 0.021 DO - 2 * t 5 Ft = DO - 2.2 * t - 0.00182 ° sat 0.3 0.025 - 2 · 0002 5 1277 = 0025-2 .2 · 0002-0 .00182 · 0025 0.3 WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 17 01/27/2009 Shell and tube heat exchanger with baffles Geometrical parameters: Inner diameter of the shell D_i 388.8 m m Diameter of the tube bundle d_b 361.2 m m Outer diameter of the tubes d_a m 25 m Tube pattern across the flow direction s_q 32 mm Tube spacing in the direction of flow along s_l 27.71 mm Pitch angle 60 ° Diameter of the baffle d_l 385.8 m m Number of baffles n_U 19 -
Diameter of the holes in the baffle d_b 25.8 mm Height of the cut in the baffle H m 77.16 m Spacing of the baffles 190 m S m Distance tube plate - 1 Baffle S_E m 290 m Number of tubes in the bundle, including n 80 - existing reactive and insulating pipes Number of tubes in the upper and lower window n_F 19 - Number of tube rows in the window zone n_RF 1.5 - Number of connection lines n_V 9 - Number of main resistances in the cross-flow zone n_W 7 - Number of main opposition in the end zone n_WE 8.5 - Distance of the outer tubes for the mantle e_1 33.22 mm Number of sealing strip pairs n_s 0 - Number of shell-side passageways ND 1 - Lane width (for ND = 2) b 49 m m Inner diameter of the inlet nozzle d_Se 159.3 mm Inner diameter of the outlet connection d_Sa 159.3 mm Media: Volume V 90.6 m³ / h Fluid: liquid or gaseous form = 0 = 1 0 Inlet pressure 400 000 Pa P_E Inlet temperature 20 ° C E J_ A J_ outlet temperature 40 ° C Average temperature 30 ° C J K density r 995.9 g / m³ Dynamic viscosity h 0.7976 mPa s Specific heat capacity 4178 J / (kg * K) Thermal conductivity l 0.6152 W / (mK) Prandtl number Pr 5416 - Average wall temperature J_ W 41.11 ° C Dynamic viscosity at average wall temperature h _ W 0.6399 m Pa s Frictional pressure loss in the exterior of the heat exchanger Dp = (n_U-1) * Nd · DP _Q = (19 - 1) · 1 × 463 P a cross-flow zone + 2 × 2 × Dp _Q_E = 478.1 Pa Endzone * Nd + n_U · DP _F = 19 ° 1 × 2226 P a window zone Dp + _S = 1588 P a connection Dp = 53 170 Pa Pressure loss in the exterior of tubular heat exchangers with and without Internals WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach Engineering 18 01/27/2009 Results - a = 1.28 - b = 1,109 - c = 1.28 - e = 7 m m Cross-flow zone L_E = 129.4 mm = 0.02459 m A_E w_e = 1023 m / s f_a_l_f = 223.4 - f_a_t_f = 0.6963 - f_a_l_v = 223.4 - f_a_t_v = 5485 - f_z_l = 0.9901 - 0.9696 = f_z_t - Xi_l = 0.006994 - xi_t = 0.4103 - 0.4047 = Xi - A_SRU = 0.00225 m² A_SMU = 0.001286 m = 0.003537 m A_SG R_M = 0.3637 - 0.1438 R_L = - r = 0.5954 - g = 106.3 ° right = 31 937 - ß = 3.7 - R_S = 0 - R_B = 0159 - A_B = 0.003911 m
f_l = 0.5646 - 0.5552 = F_B - Dp _Q_0 = 1477 Pa _Q Dp = 463 Pa Endzone Re_E = 20 924 - A_E_E = 0.03754 - 0.6704 = w_e_E - Dp _QE_0 = 861.1 - 478.1 Dp _QE = P a Windows zone A_FG = 0.01695 m = 0.004663 m A_FR A_F = 0.01229 m w_p = 2.048 m / s w_z = 1,448 m / s n_WF = 2227 - d_g = 44.41 m m m m U_F = 1107 Dp = _F_l 2100 - Dp _F_t = 3481 - Dp _F = 2226 Pa Jacket pipe w_S_E = 1,263 m / s Dp _S_E = 793.9 Pa w_S_A = 1,263 m / s Dp _S_A = 793.9 Pa _S Dp = 1588 Pa WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 19 01/27/2009 In the tube to the tubes TEMA Type AEU Medium Water Water Inlet pressure p_i 300 000 400 000 P_A Pa Pa Compression 1600000 1600000 Pa Pa The inlet temperature, 80 ° C. The i, a 20 ° C Outlet temperature Yes, i 55 ° C Yes, a 40 ° C Mean Temperature Jm, i 67.5 ° C Jm, a 30 ° C Design temperature 100 ° C 50 ° C Design pressure 400 000 500 000 Pa Pa Inlet pipe: Flanschanschlußnennweite 125 150 Outer diameter 139.7 m 168.3 m m m Nozzle wall thickness of 4 m m m 4.5 m Internal diameter 131.7 m 159.3 m m m Outlet pipe: Flanschanschlußnennweite 125 150 Outer diameter 139.7 m 168.3 m m m Nozzle wall thickness of 4 m m m 4.5 m Internal diameter 131.7 m 159.3 m m m Geometry: Sheath outer diameter 406.4 mm, since sheath thickness 8.8 mm Sat Shell inner diameter D m 388.8 m Bundle-sheath distance 13.79 m m Pipe outside diameter as 25 mm inner tube diameter d 21 mm Tube pitch (horizontal) 32 mm sq tube spacing (longitudinal) sl 27.71 mm Pitch angle 60 ° F 49 m m lane width b Spacing of the baffles 190 mm Number of baffles \ Gang 19 - RB-distance 1.Umlenkblech 290 mm diameter baffles 385.8 mm 25.8 mm hole in the baffle size of the window 20% Sealing strip pairs 0 - Number of tube side passes Z 2 - Number of shell-side passageways Z 1 - Bunch length (run) l a 4000 m m Mantle length (run) m l a 4002 m Number of tubes R 80
Kompensatordurchmesser m m Thickness (HDD) 30 m m Thicknesses (free plate) 30 m m CAD program for shell and tube heat exchanger WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 20 01/27/2009 Real log.Temperaturdifferenz and temperature distribution for the cell model Indoor temperature at 80 ° C ti1 Outside temperature at 20 ° C ta1 Mass flow on the inside Wed 72 000 k g / h Mass flow on the outside ma k 90 222 g / h Specific heat capacity on the inside cpi 4188 J / (kg * K) Specific heat capacity on the outside cpa 4178 J / (kg * K) Heat capacity flow on the inside Wwi 83 758 W / K Heat capacity flow on the outside WWA 104 697 W / K Mirror-plus shell type (Figure F3) 1 Number of tube side passes Nt 2 - Number of shell-side passageways NS 1 - Number of baffles NZ 19 - Existing heat transfer coefficient k 2565 W / (m² K) Available heat transfer area A 25.13 m ² Number of tube rows per cell 4 - Circuit: cross counter = 1; Cross DC = 2 101 - Pipe flow: the opposite direction = 1; same direction = 2 1 - Cross-mixing: 0 = none, 0.5 = total 0 - Number of cells 40 - Heat transfer product k * A 64 473 W / K Heat transfer product k * A cell per 1612 W / K Indoor temperature at 53.94 ° C ti2 Outside temperature at 40.85 ° C ta2 Efficiency of the inside of 0.4343 - Efficiency of the outside of 0.3475 - Cell efficiency inside 0.01892 - Cell efficiency outside 0.01513 - Log temperature difference in the counter-current dtGeg = 36.48 K Real-acting temperature difference dtm = 33.85 K Correction factor FN = 0.9279 - Maximum temperature on the inside timax 80 ° C Maximum temperature on the outside TAMAX 40.85 ° C Minimum temperature on the inside timin 53.94 ° C Minimum temperature on the outside of vitamin 20 ° C Max temperature inversion in a cell TINV 0 ° C Real log.Temperaturdifferenz and temperature distribution for the cell model WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process technology 21 01/27/2009 MS EXCEL Specification Sheet Project Date 27/01/2009 Fluid data Fluid Name Fluid volume, total kg / h Steam (on / off) kg / h
Fluid (on / off) kg / h Steam Water Inert Temperature (on / off) ° C 20 40 80 55 Density kg / m 995.9 979.2 Viscosity mPa.s 0.7976 0.4179 Molecular weight, vapor kg / kmol Molecular weight, inert kg / kmol Specific heat capacity J / (kg * K) 4177.6 4187.9 Thermal conductivity W / (mK) 0.6152 0.6575 Latent heat J / kg Inlet pressure (absolute) bar 4 3 Speed m / s Pressure drop, max / Prev. bar 0.53 0.18 Fouling resistance m² * K / W Power kW 2093.9 Heat transfer coefficient W / (m² K) 2565.3 Log Temp Diff. (Corrected) m (diff) 34.74 Heat transfer surface 25.1 m² Shell Side Tube Side Auslegungs-/Testdruck Pa Operating temperature ° C Number of passes 1 2 Mm corrosion allowance A Port Size & out Intermediate version M length of pipe 4-pipe material Pipe outside diameter mm 25 Number tubes 80 Transverse tube pitch 32 mm tube pitch length 27.7 Shell inside diameter mm 388.8 406.4 Admission Hood / Hood Canal Hard shell and tube floating head Floating hood flapper Y / N Baffle diameter 385.8 mm 20 Baffle spacing mm 190 19 Weather strip Expansion compensation type rv rv ² ² bundle entrance beam exit Seal coat side seal tube side - Floating Head Calculation Standards TEMA Class Weight / kg shell filled with water Weight / kg bundle Comments Number of baffles / continuity % Window Sheath outside diameter 1,02 1,47 Image (bundle / CONSTRUCTION DATA connection of an exchange arrangement) 0 0 PERFORMANCE 72000 Tube space
Water Shell side Water 90222 WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach Engineering 22 01/27/2009 CAD created with WTSC WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach process engineering 23 01/27/2009 Piezometric created with SPIE WTS example expression Thermal and hydraulic design of shell and tube heat exchangers 2009 Lauterbach Verfahrenstechnik 24 01/27/2009 Piezometric 3D with Alibre Design from SPIE Prerequisite: · LV resistance package · Alibre Design 3D CAD
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