上游充通大学 SHANGHAI JIAO TONG UNIVERSITY Engineering Thermodynamics I Lecture 19 Chapter 5 Mass and Energy Analysis of Control Volume Analysis Spring,4/5/2018 Prof.,Dr.Yonghua HUANG 强 An是A http://cc.sjtu.edu.cn/G2S/site/thermo.html 1日
Engineering Thermodynamics I Lecture 19 Spring, 4/5/2018 Prof., Dr. Yonghua HUANG Chapter 5 Mass and Energy Analysis of Control Volume Analysis http://cc.sjtu.edu.cn/G2S/site/thermo.html
Compressor and pump Inlet reciprocating Compressor: compressor work on gas raise pressure Higher pressure ratio Outlet Pump: Pump work on liquid change the state Lower pressure ratio 上游充通大学 April 5,2018 2 SHANGHAI JIAO TONG UNIVERSITY
April 5, 2018 2 Compressor and pump Compressor: work on gas raise pressure Pump: work on liquid change the state reciprocating compressor Higher pressure ratio Lower pressure ratio
Typical compressors Outlet Rotor Stator Impeller- Centrifugal Axial flow Outlet 200d 240 231 270 2526. 252 Magnets- 252a Linear compressor 260 241 (Pressure Wave 261 Generator) 9 230 282 280 242 300 Roots piston 200 293 Roots type 202 292 295 220 290 210 291 294 Inlet 上降文通大学 April 5,2018 SHANGHAI JIAO TONG UNIVERSITY
April 5, 2018 3 Typical compressors Axial flow Centrifugal Roots type Linear compressor (Pressure Wave Generator) Roots piston Magnets
1st law application Mass rate balance inlet =∑成-∑m: Compressor exit dt 立 Compressed Energy rate balance -u.-成+区（心 dt ·Wcv is primary Heat transfer secondary ·△PE&△KE<<W 上游通大学 April 5,2018 4 SHANGHAI JLAO TONG UNIVERSITY
April 5, 2018 4 1 st law application Mass rate balance Energy rate balance • Wcv is primary • Heat transfer secondary • ∆PE & ∆KE << W
Example 19.1 compressor work calculation Wey=? Determine: =1 bar Wev T =290K 1 Air 2 p2 7 bar > V=6 m/s compressor T2=450K Assumptions: A=0.1m2 V2 =2 m/s ·SS Ideal gas model Qev =-180 kJ/min ·△PE→0 Energy rate balance: 0=.-成-++-++ given =-（ given 上游充通大学 April 5,2018 5 SHANGHAI JIAO TONG UNIVERSITY
April 5, 2018 5 Example 19.1 compressor work calculation Determine: • Wcv Assumptions: • SS • Ideal gas model • ∆PE0 Energy rate balance: given given ? ?