Cycle Analysis Condenser 3 2 Compressor Throttling Valve 成 4 1 Evaporator T-s diagram? subcooling Q p-h diagram? evap TA △Tc 2 P Tcond 3 Pcond 女T Pevap 4 superheat:△Th h 上游充通大率 May11,2018 6 SHANGHA BAO TONG LINIERSITY
May 11, 2018 6 Cycle Analysis P h 3 2 4 1 pcond pevap s T 2 1 3 4 Tcond Tevap T H T L subcooling Tsc superheat: Tsh Compressor Throttling Valve Condenser 1 3 2 4 Evaporator W Qcond Q evap T‐s diagram? p‐h diagram?
Cycle Analysis Typical Assumptions specified evaporating(Tevap)and condensing (Tcond) temperatures specified superheat entering the compressor specified subcooling leaving the condenser constant pressure throughout heat exchangers negligible kinetic and potential energy changes for all components adiabatic throttling valve specified isentropic efficiency for compressor adiabatic compressor 上游充通大率 May11,2018 7 SHANGHAI BAO TONG LINIERSITY
May 11, 2018 7 Cycle Analysis Typical Assumptions • specified evaporating ( Tevap) and condensing ( Tcond) temperatures • specified superheat entering the compressor • specified subcooling leaving the condenser • constant pressure throughout heat exchangers • negligible kinetic and potential energy changes for all components • adiabatic throttling valve • specified isentropic efficiency for compressor • adiabatic compressor
Cycle Analysis Compressor Inlet State P1=Pevap h1=h (Tevap+ATsh,Pevap) Compressor Outlet State P2 =Pcond TA isentropic specific work Tcond h2 =h+(h2sh) isentropic efficiency S h2s=h(p2,S2=S1) 上游充通大率 May11,2018 8 SHANGHAI BAO TONG LINIERSITY
May 11, 2018 8 Cycle Analysis Compressor Inlet State p 1 = pevap h 1 = h (Tevap + Tsh , pevap ) Compressor Outlet State p 2 = pcond h2s = h (p 2 , s 2 = s 1 ) isentropic specific work 2s 1 2 1 s isentropic efficiency (h h ) h h T s 2 Tcond Tevap p 2 1 2s
Cycle Analysis Condenser Outlet State P 3 P3=Pcond Pcond h3=h (Tcond+ATsc,Pcond) L negative Pevap Evaporator Inlet State p4 =Pevap h4=h3 上游充通大率 May11,2018 9 SHANGHAI BAO TONG LINIERSITY
May 11, 2018 9 Cycle Analysis Condenser Outlet State p 3 = pcond h 3 = h (Tcond + Tsc , pcond ) Evaporator Inlet State p 4 = pevap h 4 = h 3 P h 3 4 Pcond negative Pevap