VERD Table of contents Sample Printout
Transcription
VERD Table of contents Sample Printout
VERD 2014 Sample Printout Table of contents Table of contents ................................................................1 Vaporization of pure substances in shell-and-tube heat exchangers ................2 Design of the tube sheet Determination of the tube sheet data ....................4 Determination of properties ......................................................6 Properties of water ..............................................................7 Real logarithmic temperature difference for different exchanger types ............9 Pressure drop in flow through evaporator tubes ..................................10 Heat transfer during boiling of saturated liquids - flow patterns - .............12 Heat transfer during boiling of saturated liquids -nucleate boiling horizontal- .14 CAD program for shell and tube heat exchangers ..................................16 Layout Input values: Calculated values: Critical values: Estimated values: Lauterbach Verfahrenstechnik GmbH 1.234 1.234 1.234 1.234 or or or or 1 1.234 1.234 1.234 1.234 2014 VERD 2014 Sample Printout Vaporization of pure substances in shell-and-tube heat exchangers Tube-side: Tube-side vaporization Medium: n-pentane Mass flow mi 7200 kg/h Volume flow Vi 13.22 m³/h Pressure in abs. Pi 5 bar Inlet temp. 92.49 °C ϑei Outlet temp. 92.69 °C ϑai Mean temp. m 92.59 °C i ϑ Shell-side: (Condensation) Medium: Steam condensation Mass flow ma 1038 Volume flow Va 388.9 Pressure in abs. Pa 5 Inlet temp. 151.9 ϑea Outlet temp. 151.7 ϑaa Mean temp. m 151.8 a ϑ Liquid fraction (Inlet) Liquid fraction (Outlet) xi 1 - xo 0 - Vapour fraction (Inlet) Vapour fraction (Outlet) Heat duty Qi 607.9 Fouling fi 0 Liquid phase Density ρi Spec. heat cap. cpi Dyn. viscosity ηi Thermal cond. λi Surface tension σi Critical press. Pc Molecular weight MW 544.8 2679 0.1248 0.1059 8.241 3370000 72.15 Vapour phase Density 13.75 ρi Spec. heat cap. cpi 2118 Dyn. viscosity 0.008833 i η Thermal cond. 0.0216 λi Heat of evaporation 303400 ∆hv Reference Reference Reference Reference Reference Reference Reference kW Heat duty Heat loss m²·K/W Fouling 1 - xo 0 - Qa Qva -607.9 0 fa 0 Vapour phase kg/m³ Density ρa J/(kg·K)Spec. heat cap. cpa mPa·s Dyn. viscosity ηa W/(m·K) Thermal cond. λa Heat of J/kg evaporation ∆hv Final bundle length Heat transfer area Performance factor of the heat exchanger Lauterbach Verfahrenstechnik GmbH xi Liquid phase kg/m³ Density 915 ρa J/(kg·K)Spec. heat cap. cpa 4315 mPa·s Dyn. viscosity 0.1802 ηa W/(m·K) Thermal cond. 0.6833 λa mN/m Surface tension σa 48.36 Pa Critical press. Pc 2.206E+7 kg/kmol Molecular weight MW 18.02 data: heat flux heat transfer coefficient heat of evaporation density of the liquid density of the vapour surface tension 2 q0 α0 ∆hv0 ρ F,0 ρ D,0 σ0 20000 3070 321200 564.4 9.341 9.882 la A 1512 2.945 1.15 kg/h m³/h bar °C °C °C kW kW m²·K/W kg/m³ J/(kg·K) mPa·s W/(m·K) mN/m Pa kg/kmol 2.669 2413 0.01402 0.03103 kg/m³ J/(kg·K) mPa·s W/(m·K) 2107420 J/kg W/m² W/(m²·K) J/kg kg/m³ kg/m³ mN/m (at (at (at (at Pc/10) Pc/10) Pc/10) Pc/10) mm m² - 2014 VERD 2014 Sample Printout Geometry: Description of type: Installation position: horizontal Straight tubes with fixed tubesheets Shell outside diam. Do Shell inside diam. Di Bundle-shell distance Tube outside diam. do Tube inside diam. di Tube pitch (crosswise) Pitch angle Φ 188.9 176.3 12 20 16 25 60 mm mm mm mm mm mm ° Shell without baffles Shell wall thickness sa 6.3 mm Min. bundle-shell dist. Tube wall thickness si 12 2 mm mm 21.65 40 0.002 mm mm mm Tube pitch (lengthwise) Lane width b Arithmetic mean Ra roughness height of tubes — Tube material Thermal conductivity of tube material Steel λt Number of tube-side passes 1 Results: Number of tubes Heat transfer coefficient (tube-side) Heat transfer coefficient (shell-side) Overall heat transfer coefficient Logarithmic mean temperature diff. LMTD FN Factor (Correction factor for LMTD) Total fouling resistance Allowable superheating for condensation Tube-side: Velocity (Inlet) Velocity (Outlet) Pressure drop ∆pi Wall temperature ϑwi 0.589 23.34 12017 113 Inlet nozzle Nominal width Outside diameter Inside diameter Velocity DN 50 60.3 54.5 1.574 Outlet nozzle Nominal width Outside diameter Inside diameter Velocity DN 100 114.3 107.1 16.15 Valuation: Actual performance Nominal performance Performance factor Actual heat flux Critical heat flux Lauterbach Verfahrenstechnik GmbH 699.1 607.9 1.15 237354 374375 52 m/s m/s Pa °C mm mm m/s mm mm m/s R αi αο k ∆ϑ FN f ϑs 31 14523 8287 4006 59.25 1 0 5.781 W/(m·K) - W/(m²·K) W/(m²·K) W/(m²·K) K m²·K/W °C Shell-side: Velocity shell-side 7.364 m/s Pressure drop ∆pa Wall temperature ϑwa 123.2 Pa °C Inlet nozzle Nominal width Outside diameter Inside diameter Velocity ρ ·v² Inlet nozzle DN 80 88.9 82.5 20.21 1090 mm mm m/s kg/(m·s²) Outlet nozzle Nominal width Outside diameter Inside diameter Velocity DN 20 26.9 22.3 0.8068 mm mm m/s kW kW W/m² W/m² 3 2014 VERD 2014 Sample Printout Design of the tube sheet Determination of the tube sheet data Name of type: Baffle-type: Without baffles Design = D; Rating / Simulation = R < R > Outside shell diameter Inside shell diameter Bundle diameter Minimum distance bundle - shell Distance between bundle - shell Do Di Db Dm D 188.9 176.3 152.3 12 12 mm mm mm mm mm Outside tube diameter Inside tube diameter Pitch crosswise to direction of flow Pitch in direction of flow Pitch angle da di sq sl Φ 20 16 25 21.65 60 mm mm mm mm ° Tube pattern: aligned = a / staggered = s < S Arrangement: around central tube = 0 staggered by 1/2 pitch = 1 < 0 > - < 1 1 0 > 40 40 mm mm Number of tube-side passes Number of shell-side passes Bundle type Tube lane width (horizontal) Tube lane width (vertical) Outside head diameter Bolt-circle diameter Number of bolts on the bolt-circle Rotation angle for bolt-hole pattern > Da Dt mm mm ° Number of tubes Number of dummy tubes Number of tie rods Total number of tubes, dummy tubes and tie rods Number of boundary tubes required/actual RR n nB nZ nG Sum of the shortest connecting paths in the center Shortest connecting path between tube and tube Shortest connecting path between tube and shell Number of connecting paths Mean distance boundary tubes-envelope circle centre Le e e1 nV rh / Number of tubes, dummy tubes and tie rods per pass Pass-No. 1 2 3 4 5 31 0 0 0 0 Final tube length Total area Number of exchangers in series la A Nozzles: Inside diameter of the inlet nozzle Inside diameter of the outlet nozzle 1512 2.945 1 31 0 0 31 26 76.29 5 28.14 4 53.98 6 0 - mm mm mm mm 7 0 8 0 mm m² - Tube-side 54.5 mm 107.1 mm Shell-side 82.5 mm 22.3 mm — Lauterbach Verfahrenstechnik GmbH 4 2014 VERD 2014 Sample Printout Lauterbach Verfahrenstechnik GmbH 5 2014 VERD 2014 Sample Printout Determination of properties Properties Name: Tube-side medium: n-pentane Temperature ϑ 92.59 °C Pressure p 500000 Pa Properties of the boiling liquid: Density Specific heat capacity Dynamic viscosity Kinematic viscosity Thermal conductivity Prandtl number Surface tension 545 ρ cp 2679 0.1248 η 2.29E-07 ν 0.1059 λ Pr 3.157 8.241 σ kg/m³ J/(kg·K) mPa·s m²/s W/(m·K) mN/m 13.76 ρ cp 2118 0.00883 η ν 6.417E-7 0.0216 λ Pr 0.8658 kg/m³ J/(kg·K) mPa·s m²/s W/(m·K) - Properties of the saturated vapour: Density Specific heat capacity Dynamic viscosity Kinematic viscosity Thermal conductivity Prandtl number Heat of evaporation Critical pressure Molecular weight ∆hv 303400 Pc M 33.7 72.15 J/kg bar kg/kmol Reference values at a reduced pressure of 0.1 · Pc : Reduced Heat of Density Density Surface pressure evaporation of boiling liquid of saturated vapour tension Lauterbach Verfahrenstechnik GmbH pr = Pc /10 ∆hv* ρL ρG σ∗ 6 337000 Pa J/kg kg/m³ kg/m³ mN/m 2014 VERD 2014 Sample Printout Properties of water Properties of Water and Steam State 1 Calculation for saturation? (Yes = Y / No = N) Temperature Pressure ϑ1 p1 < Y State 2 > 151.8 5.001 < N °C bar ϑ1 p2 Properties of liquid water or superheated steam: State 1 Liquid ρ cp λ η ν Pr a v cv h u s Z σ β κ w ε Properties of vapour fraction of wet steam: State 1 Density 2.669 kg/m³ ρ Spec.isob.heat capacity cp 2413 J/(kg·K) Thermal conductivity 0.03103 W/(m·K) λ Dynamic viscosity 0.01402 mPa·s η Kinematic viscosity m²/s 0.000005 ν Prandtl number Pr 1.09 Thermal diffusivity a 4.82E-06 m²/s Specific volume v 0.3747 m³/kg Spec.isoc.heat capacity cv 1761 J/(kg·K) Specific enthalpy h 2748117 J/kg Spec. internal energy u 2560712 J/kg Specific entropy s 6821 J/(kg·K) Compressibility Z 0.9554 C. of therm. expansion β 0.002935 1/K Isentropic exponent 1.301 κ Speed of sound w 493.8 m/s Dielectric constant 1.023 ε ρ cp λ η ν Pr a v cv h u s Z β κ w ε Lauterbach Verfahrenstechnik GmbH ρ cp λ η ν Pr a v cv h u s Z σ β κ w ε 915.3 4315 0.6836 0.1802 1.969E-7 1.138 1.731E-7 0.001093 3518 640218 639671 1861 0.002786 48.35 0.001037 3912 1462 43.65 7 123.3 5 °C bar State 2 Liquid kg/m³ J/(kg·K) W/(m·K) mPa·s m²/s m²/s m³/kg J/(kg·K) J/kg J/kg J/(kg·K) mN/m 1/K m/s - Density Spec.isob.heat capacity Thermal conductivity Dynamic viscosity Kinematic viscosity Prandtl number Thermal diffusivity Specific volume Spec.isoc.heat capacity Specific enthalpy Spec. internal energy Specific entropy Compressibility Surface tension C. of therm. expansion Isentropic exponent Speed of sound Dielectric constant > 940.6 4251 0.6843 0.2255 2.398E-7 1.401 1.711E-7 0.001063 3652 517867 517336 1563 0.002906 54.31 0.000875 4327 1517 49.87 kg/m³ J/(kg·K) W/(m·K) mPa·s m²/s m²/s m³/kg J/(kg·K) J/kg J/kg J/(kg·K) mN/m 1/K m/s - State 2 kg/m³ J/(kg·K) W/(m·K) mPa·s m²/s m²/s m³/kg J/(kg·K) J/kg J/kg J/(kg·K) 1/K m/s - 2014 VERD 2014 Sample Printout Heat of evaporation Entropy of evaporation Fraction vaporized Enthalpy of wet steam Entropy of wet steam Characteristics: Molar mass Gas constant Critical temp. Critical pressure Critical density ∆hv ∆sv x hx sx M 18.02 R 461.5 Tc 373.9 pc 2.206E+7 322 ρc Lauterbach Verfahrenstechnik GmbH 2107899 4960 J/kg J/(kg·K) J/kg J/(kg·K) g/mol J/(kg·K) °C Pa kg/m³ 8 ∆hv ∆sv x hx sx Validity: 0.01 °C ≤ ϑ 0.00612 bar 0.01 °C ≤ ϑ 0.00612 bar J/kg J/(kg·K) J/kg J/(kg·K) ≤ ≤ ≤ ≤ 800 °C p ≤ 1000 bar 2000 °C p ≤ 500 bar 2014 VERD 2014 Sample Printout Real logarithmic temperature difference for different exchanger types Real logarithmic temperature difference for different heat exchanger types Shell and tube heat exchanger Code number for exchanger type < 50 > Inlet temperature outside Outlet temperature outside ϑa1 ϑa2 151.9 151.7 °C °C Inlet temperature inside Outlet temperature inside ϑi1 ϑi2 92.49 92.69 °C °C Logarithmic temperature difference (counterflow) Correction factor dϑ = 59.25 K FN = 1 - ⇒ Real logarithmic temperature difference dϑm = 59.25 K Lauterbach Verfahrenstechnik GmbH 9 2014 VERD 2014 Sample Printout Pressure drop in flow through evaporator tubes Calculation of local variables Properties: Density of the liquid phase Density of the vapor phase Dynamic viscosity of the liquid phase Dynamic viscosity of the vapor phase ρ _l ρ _g η_l η_g 544.8 13.75 0.1248 0.008833 Geometrie: Length of evaporator tube Inside tube diameter Relative tube roughness Angle of inclination of tubes l d k/d θ 1512 16 0.00625 0 Boundary conditions: Mass flow Vapour mass fraction Vapour mass fraction at the inlet Vapour mass fraction at the outlet Number of iteration steps Speed of sound in vapour m x x1 x2 n a = ⇒ Froude number ⇒ Auxiliary value of Froude number ⇒ ⇒ Liquid volume fraction Fr HW 1/β β 320.9 0.5 0 1 4 211.1 = 87.57 = 48.05 = 3.910E+7 = 2.557E-8 kg/m³ kg/m³ mPa·s mPa·s mm mm ° kg/(m²·s) m/s - [3] [2b] [2a] Determination of either disperse or coherent phase: 1/β 3.910E+7 ≤ HW 48.05 coherent ⇒ [2] 1. Local fluid friction pressure drop a) Vapour phase disperse ⇒ ⇒ ⇒ ⇒ Two phase Reynolds number Drag coefficient K2 for β ≤ 0.4 or β > 0.4 Local fluid friction pressure drop Re_ZP ξ K2 dp/dl = = = = 53587 0.034 1.007 1999 Pa/m [6] [5] [7]/[8] [4] Fr_1 Re_1 ψ ε _2 ε _1 ε γ _E γ _F E Φ ξ dp/dl = = = = = = = = = = = = 2.27E-12 0.04168 0.000001 0.000013 0.001288 0.000013 0.002286 0.002292 0.7809 1.005 0.01281 3011 Pa/m [21] [20] [19] [18] [16]/[17] [15] [14] [13] [12] [11] [10] [9] b) Vapour phase coherent ⇒ Froude number 1 ⇒ Reynolds number 1 ⇒ ⇒ ⇒ ⇒ ⇒ ⇒ ⇒ ⇒ ⇒ Drag coefficient ⇒ Local fluid friction pressure drop — Lauterbach Verfahrenstechnik GmbH 10 2014 VERD 2014 Sample Printout 2. Local static pressure drop Range differentiation for 1/β : Range Range Range Range 1: 2: 3: 4: 1/β HW 500 1/β ≤ < < > HW 1/β ≤ 500 1/β ≤ 10000 10000 1/β = 3.910E+7 HW = 48.05 Range 4 ⇒ Range K κ _tt H2 H1 H α ⇒ ⇒ ⇒ ⇒ ⇒ ⇒ Vapour volume fraction ⇒ Local static pressure drop 1 = 0.9839 = 0.08459 = 0.07799 = 0.0822 = 2.557E-8 = 1 dp/dl = 0 2 3 4 [24] [29] [28] [27] [26] [30] [31] [23] [25] [25] [25] Pa/m [22] kg·m/s² [33] 3. Acceleration pressure drop · Momentum flux I = 1.506 4. Integration with the evaporator tube length ∆p_R = ∆p_S = ∆p_B = 4718 0 7299 Pa Pa Pa [21a] ∆p_tot = 12017 Pa [1] ⇒ Fluid friction pressure drop ⇒ Static pressure drop ⇒ Acceleration pressure drop ⇒ Total pressure drop Lauterbach Verfahrenstechnik GmbH 11 [34a] 2014 VERD 2014 Sample Printout Heat transfer during boiling of saturated liquids - flow patterns Flow patterns in horizontal and slightly inclined tubes Input variables: Hydraulic diameter of the pipe d mm 16 · Flow vapour content x 0.9 kg/kg · Mass flow density m 320.9 kg/(m²·s) Surface tension of the fluid σ 8.241 mN/m Density of the liquid phase ρL 544.8 kg/m³ Density of the vapour phase ρG 13.75 kg/m³ Dynamic viscosity of liquid phase ηL 0.1248 mPa·s Dynamic viscosity of vapour phase ηG 0.008833 mPa·s Angle of inclination of the pipe Θ ° ( ≤ 10° ) 0 Design variables: · X = f ( x ¡ f ( ¡ 0.9 ; ρG ; ρL ; ηG ; ; 13.75 ; 544.8 ; 0.008833 ; ) ) 0.1248 0.03235 ξ L = 0.3164 / ReL 0.25 ¡ 0.3164 / · m · (1 - ReL = 320.9 · (1 - · 0.25 ¡ 0.03951 x ) · 0.9 ) · d / 0.016 / ηL 0.1248 ¡ 4114 · ReG = m · ReG = 320.9 · (ReL FrG ')0.5 4114 · ReL = x 0.9 · d / ηG · 0.016 / 0.008833 ¡ 523110 ¡ · · ¡ f ( m ¡ f ( 320.9 ; ¡ ηL ; x 0.9 ; ρG ; ρL ; ; 13.75 ; 544.8 ; ηL 0.1248 ; ; Θ ) 0 ) 547.1 — Lauterbach Verfahrenstechnik GmbH 12 2014 VERD 2014 Sample Printout FrGm 0.5 ¡ · ¡ f ( ¡ f ( ¡ · m ; 320.9 x ; ; 0.9 d ; 0.016 ; ρL ; ρG ) ; 544.8 ; 13.75 ) ; ρL ; ; 544.8 ; 8.422 (Fr Eu)L 0.5 ¡ · ¡ f ( ¡ f ( ¡ ξL ρG ; ; ; ; 0.03951 13.75 · m Θ 320.9 0 ; ) x ; ; ) 0.9 ; d 0.016 0.02116 (We/Fr)L ¡ f ( d ¡ f ( ~ h = 0.05859 0.016 ε = ~ ~ fL = f ( h ) ¡ f ( ; 0.05859 ; Φ = ) ¡ 8.241 ) ) ¡ 166 5.445 0.01857 0.01857 0.05859 σ ; 544.8 0.9848 ~ ~ fG = π / 4 - fL ¡ π / 4 ~ ~ Ui = f ( h ) = f ( ρL ; ) ¡ ¡ 0.7668 0.4697 Flow pattern: 0 1 2 3 4 5 6 7 = = = = = = = = Unknown flow Stratified flow Wave flow Bubble flow Slug / plug flow Turbulent gas and laminar liquid flow Mist flow Annular flow ⇒ Flow pattern: Lauterbach Verfahrenstechnik GmbH 7 13 2014 VERD 2014 Sample Printout Heat transfer during boiling of saturated liquids -nucleate boiling horizontalNucleate boiling in horizontal tubes Boundary conditions: 0 = Constant wall temperature 1 = Constant heat flux 0 Type of substance: 0 = Non-cryogen 1 = Cryogen 0 Input variables: Mass flow Number of tubes Inside tube diameter Tube wall thickness Thermal conductivity of tube ⇒ Wall heat conduction Arithmetic mean roughness height m n di s λw λ w ·s Ra 16 2 52 0.104 0.002 kg/h mm mm W/(m·K) W/K mm 320.9 kg/(m²·s) · Mass velocity m · Vapour mass fraction x 0.9 kg/kg · Heat flux Pressure Critical pressure Reduced pressure p / pc q p pc = p* Properties: Density of the liquid phase Density of the vapour phase Heat of evaporation Surface tension of the medium 237354 500000 3370000 0.1484 W/m² Pa Pa - ρL ρG ∆hv σ 544.8 13.75 303400 8.241 kg/m³ kg/m³ J/kg mN/m Properties at reference boiling pressure p0 = 0.1 · pc : Density of the liquid phase Density of the vapour phase Heat of evaporation Surface tension of the medium p0 = 337000 Pa ρ L0 ρ G0 ∆hv0 σ0 564.4 9.341 321200 9.882 kg/m³ kg/m³ J/kg mN/m Molecular weight of the medium Correction factor M CF 72.15 1.169 kg/kmol - d0 Ra0 10 0.001 mm mm 20000 3070 W/m² W/(m²·K) Reference values: Tube diameter Arithmetic mean roughness height · Heat flux Heat transfer coefficient q0 α0 (Reference value for the heat transfer coefficient in nucleate boiling at q0 , p0 and Ra0 = 1.0 µm) Correction factors: Correction factor κ 1 Coordinate in direction of flow z = Correction factor ψ 327.6 mm 1 — Lauterbach Verfahrenstechnik GmbH 14 2014 VERD 2014 Sample Printout Flow patterns: 1 = Stratified flow 2 = Wavy flow 3 = Bubble flow 4 = Slug or plug flow 5 = Turbulent gas and laminar liquid flow 6 = Mist flow 7 = Annular flow ⇒ Flow pattern: 7 - Design variables: p* = p / pc = n(p*) = 0.6191 F(p*) = 1.185 F(d) = 0.7906 = 1.097 = 0.4761 F(W) · 500000 / · α(z)B n q = ψ · CF · · · · F(p*) · F(d) · F(W) · F(m;x) · q0 237354 = 0.1484 · F(m;x) α0 3370000 = 1 · 0.6191 1.169 · · 1.185 · 0.7906 · 1.097 · 0.4761 20000 = 2.646 ⇒ α(z)B = 8122 Lauterbach Verfahrenstechnik GmbH W/(m²·K) 15 2014 VERD 2014 Sample Printout CAD program for shell and tube heat exchangers Tube-side TEMA type AEL TEMA: Front end: A Medium Inlet pressure Pressure stage Inlet temperature Outlet temperature Mean temperature Design temperature Design pressure Shell: Shell-side E Rear end: n-pentane pi ϑe,i ϑa,i ϑm,i L Steam condensation 500000 800000 92.49 92.69 92.59 110 600000 Pa Pa °C °C °C °C Pa 50 60.3 2.9 54.5 mm mm mm 100 114.3 3.6 107.1 mm mm mm pa ϑe,a ϑa,a ϑm,a 500000 800000 151.9 151.7 151.8 180 600000 Pa Pa °C °C °C °C Pa 80 88.9 3.2 82.5 mm mm mm 20 26.9 2.3 22.3 mm mm mm Inlet nozzle: Flange connection n.w.* Outside diameter Nozzle wall thickness Inside diameter DN DN Outlet nozzle: Flange connection n.w.* Outside diameter Nozzle wall thickness Inside diameter DN DN * n.w. = nominal width Geometry: Shell outside diam. Do Shell inside diam. Di Bundle - shell distance Tube outside diam. do Tube pitch (crosswise) Pitch angle Φ Central baffle spacing Inlet baffle spacing Baffle borehole Sealing strips pairs 188.9 176.3 12 20 25 60 mm mm mm mm mm ° mm mm mm - Number of passes (tube-side) Number of passes (shell-side) 6.3 mm Tube inside diameter di Tube pitch(lengthwise) Pass lane width b Number of baffles/pass Baffle diameter Baffle cut 16 21.65 40 mm mm mm mm % 1 1 Final bundle length Final shell length la la Number of tubes Expansion joint diameter Plate thickness (fixed plate) Plate thickness (free plate) R Lauterbach Verfahrenstechnik GmbH Shell wall thickness sa 1512 1512 mm mm 31 30 30 16 - mm mm mm 2014