增压器匹配

Turbocharger 涡 轮 增 压 器
Characteristic values: (John B. Heywood: „Internal Combustion Engine Fundamentals“, McGraw-Hill Book Company)
& cor = m N cor
& T0,in m p0,in
Some manufacturers’ definitions
Asea Brown Boweri:
Compressor:
corrected speed N corr = n Tref T1 [ s −1 ] & =V & T T [m 3 s] corrected volume flow V corr 1 ref 1
,
corrected massflow corrected compressor speed
N = T0,in
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TC Simplified Model - Basic Equations
Corrected to map reference values: 根据标准条件进行换算 ：
(John B. Heywood: „Internal Combustion Engine Fundamentals“, McGraw-Hill Book Company)
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TC Simplified Model - Max. Torque
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TC Simplified Model - Max. Torque
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TC Simplified Model - Max. Torque
•在涡轮机选型的时候，需要 选择turbine layout这种方式 •此时discharge coefficient这 是数值是计算的初始估计值 。程序会根据用户设定的目 标压力计算出这个量的实际 数值，推荐这个初始值设置 为0.1 •另外压气机的效率和涡轮机 的效率是输入的边界条件， 其数值的选取用户可以根据 涡轮增压器的特性图进行估 计，对于增压器来讲，最大 扭矩点接近增压器的最高效 率区，涡轮机可根据估计的 膨胀比查出相应的效率数值
AVL BOOST Turbocharger Matching
Boost_support_china@avl.com
Intro Turbo Charger Models Introduction BOOST提供两种涡轮增压器模式： 提供两种涡轮增压器模式：
简化模式： 简化模式：
使用第一种模式（简化模式）的优点是只需很少的输入参数 。在发动机稳定运转时，压气机的增压比，压气机和涡轮机 的效率，涡轮的通流能力均保持恒定，由此程序提供了三种 计算模式： • 确定尺寸涡轮下的增压比计算模式 • 确定增压比下的涡轮设计模式 • 放气阀计算模式
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Some manufacturers’ definitions
KKK: Compressor:
corrected speed N =n T T [min − 1] corr ref 1t
& & T corrected volume flow V =V T [ m3 / s ] corr 1t ref 1t p & & ref corrected massflow m =m corr p1t T T [kg / s] 1t ref
& cor = m N cor =
& T0,in Tstd m p0,in pstd N T0,in Tstd ,
,
corrected massflow corrected speed reference values
pstd , Tstd
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TC Simplified Model - Basic Equations Compressor Efficiencies 压气机效率:
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TC Simplified Model - Max. Torque
Load the model “ TC_simple_basic.bwf” and store it as “TC_simple_1200.bwf”
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TC Simplified Model - Max. Torque
1200rpm为 最大扭矩点
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Some manufacturers’ definitions
Garrett:
Compressor:
corrected speed N corr = n T ref T1t [min & corr = m & corrected massflow m p ref p1t
−1
]
T T [ lb / min] 1t ref
涡轮机膨胀比与动轮速比之间的关系： 涡轮机膨胀比与动轮速比之间的关系：
d t Πncor a= p4 κκ−1 1- ( ) p 03
a dt κ R p4 p03 Π
κ −1 2 Rκ
blade speed ratio 动轮速比 turbine wheel diameter 动轮直径 ratio of specific heat (ca. 1.36) 比热比 gas constant (ca. 287 J/kg/K) 气体常数 turbine outlet static pressure 涡轮机出口静压 turbine inlet total pressure 涡轮机进口总压 3.14159....
Mass flow = 0.127kg/s Temperature = 298K p0= 0.0956Mpa => Corrected mass flow = 22.93kg*sqrt(K)/(s*MPa) Pressure ratio = 1.46
112.930
Total - to -Total Pressure Ratio
全模式
全模式计算中考虑了压气机和涡轮机转子的转动惯量。计算 过程中每一计算步长上，涡轮增压器的运转特性将根据瞬时 的转子速度，流量和压比插值得到。当发动机瞬态运转时， 由于涡轮增压器的运转特性随时间变化，需要采用这种模式 。
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TC Simplified Model - Basic Equations
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Main Engine Data
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对于中小型的柴油机和增压汽油机，其匹配的涡轮增压器往往是带有废气放气阀的，放 气阀在最大扭矩点之后开启。因此在一开始的涡轮机选型的过程中，可以选择最大扭矩 点作为计算始点。针对不带有放气阀的大型柴油机，可以选择标定点作为匹配计算的开 始点。 首先进行涡轮机的选型，此时需要用户估计匹配点的增压压力，具体公式如下（可参考 BOOST用户手册：BOOST_UsersGuide.pd第七章涡轮增压器匹配一节）：
pressure ratio, Efficiency : total to total
Turbine:
& corr = corrected massflow m
& T3t kg K m p3t s ⋅ bar pressure ratio : total to static
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pressure ratio, efficiency : total to static
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Intro Turbo Charger Models Introduction
Design Targets:
设计目标： 设计目标：
• Maximum Torque : 1200 rpm • Low End: • Rated Speed: 800 rpm 1800 rpm
ηCTT
p02 Fra Baidu bibliotek−1 T0 S 2 − T01 p01 = = T02 T02 − T01 −1 T01
κ −1 κ
κ 1 −1 & 1c p ,1To1 p02 κ1 m & = −W − 1 C ηCTT p 01
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98.200
3,5
88.380 75 78.580 77 79 68.740 70
ηTTS =
T03 − T04 = T03 − T4 S
p4 1− p 03
κ −1 κ
κ 4 −1 κ 4 p04 1 − & =m & W c η T T 4 p , 4 TTT 03 p03
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TC Simplified Model - Basic Equations Relation of turbine pressure ratio and blade speed ratio:
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TC Simplified Model - Low End
800rpm为 低速点
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TC Simplified Model - Low End
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TC Simplified Model - Low End
COMPRESSOR MAP
without Reference
5 4,5 Speed parameter N/SQRT(T) - [rps/SQR(K)]
1200 rpm
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TC Simplified Model - Max. Torque
95
Reduced massflow [(kg*SQRT(T)/(s*Mpa)] 0,7
90 85 80 75 70 65 60 55 50 45 40 35 1 1,5 2
Pressure ratio
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Mass flow = 0.3029kg/s T3 = 1049 K; p3= 0.178MPa => Corrected mass flow = 55.1
pressure ratio, efficiency : total to total T ref [ ° R ]
Turbine:
corrected speed N corr = n [min −1 ] T3t Tref & T3t Tref m p3t pref [lb / min]
& corr = corrected massflow m
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TC Simplified Model - Basic Equations Turbine Efficiencies 涡轮机效率:
ηTTT =
T03 − T04 = T03 − T04 S
T04 1− T03 p04 1− p 03 T04 1− T03
κ −1 κ
For sonic flow
ψ = ψ max =
2 κ + 1
κ κ −1
1 κ −1
⋅
κ κ +1
Critical pressure ratio
pk 2 = p0 κ + 1
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TC Simplified Model - Low End
Store file as: TC_800_simp.bwf and start calculation
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TC Simplified Model - Max. Torque
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TC Simplified Model - Max. Torque
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TC Simplified Model - Max. Torque
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TC Simplified Model - Max. Torque
Mass flow = 0.2922kg/s Temperature = 297.7K p0= 0.09519Mpa => Corrected mass flow = 52.96kg*sqrt(K)/(s*MPa) Pressure ratio = 2.3
1200 rpm
0,6
0,5
Pressure ratio = 1.71
0,4
0,3
1200 rpm
0,2
0,1
2,5
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TC Simplified Model - Max. Torque
Turbine Discharge Coefficient = Aeffective/Ageom≅ 0.1413
Effective Area
• m To R −1 ⋅ ψ Aeff = po 2
κ +1 2 κ p2 κ p2 κ ψ= ⋅ − κ − 1 po1 po1
For subsonic flow