朗肯循环热力学性能.rar_matlab__matlab_

%% 该程序探讨蒸发温度对朗肯循环子系统热力学性能的影响 clc; clear; %% 已知的外部量 T0 = 293.15; %T0环境温度,K T5 = 763.15; %热源入口温度,K T7 = 293.15; %冷却水进口温度,K m1 = 50; %进入朗肯循环系统的热源流量,kg/s Fluid_Rankine = 'WATER'; %朗肯循环工质 Fluid_System = 'HELIUM'; %系统工作-氦气 %% 和冷凝器内工质有关的已知量 Tc = 318.15; %冷凝温度，K T3 = Tc-5; %T3根据过冷度（5 ℃）计算 Pc = refpropm('P','T',Tc,'Q',1,Fluid_Rankine); %冷凝压力由冷凝温度和干度=1求得,kPa h3 = refpropm('H','T',T3,'P',Pc,Fluid_Rankine); %冷凝器出口状态点焓值,J/kg s3 = refpropm('S','T',T3,'P',Pc,Fluid_Rankine); %冷凝器出口状态点熵值,J/(kg K) %% 蒸发温度变化范围 n = 101; %设定的输出数据点个数 Te = 523.15:120/(n-1):643.15; % Te蒸发温度 %% 循环计算 for i = 1:n %% RC循环中与蒸发器内工质有关的量 Pe(i) = refpropm('P','T',Te(i),'Q',1,Fluid_Rankine); %蒸发压力根据蒸发温度和干度=1确定,kPa T1(i) = Te(i)+30; %T1根据过热度(30℃)计算 h1(i) = refpropm('H','T',T1(i),'P',Pe(i),Fluid_Rankine); %过热点温度和压力确定点1焓值,J/kg s1(i) = refpropm('S','T',T1(i),'P',Pe(i),Fluid_Rankine); %过热点温度和压力确定点1熵值,J/(kg K) h2s(i) = refpropm('H','P',Pc,'S',s1(i),Fluid_Rankine); %膨胀机等熵膨胀理想点,J/kg h2(i) = h1(i)-0.8*( h1(i)- h2s(i)); %根据膨胀机效率（0.8）计算冷凝器入口焓值,J/kg s2(i) = refpropm('S','P',Pc,'H',h2(i),Fluid_Rankine); %冷凝器入口处的熵值,J/(kg K) h4s(i) = refpropm('H','P',Pe(i),'S',s3,Fluid_Rankine); %泵等熵膨胀理想点,J/kg h4(i) = h3+(h4s(i)-h3)*1.33; %根据泵效率（0.75）计算,J/kg s4(i) = refpropm('S','P',Pe(i),'H',h4(i),Fluid_Rankine); %蒸发器入口熵值,J/(kg K) %% 有关热源的量 P_hs = 3000; %热源压力，kPa h5 = refpropm('H','T',T5,'P',P_hs,Fluid_System); %热源进口焓值,J/kg s5 = refpropm('S','T',T5,'P',P_hs,Fluid_System); %热源进口熵值,J/(kg K) %% 计算蒸汽流量并根据蒸汽流量算热源出口的相关量 m3(i) = m1*(h5-h6(i))/(h1(i)-h4(i)); %蒸汽流量,kg/s h6(i) = h5-(m3(i)*(h1(i)-h4(i)))/m1; %热源出口焓值,J/kg T6(i) = refpropm('T','H',h6(i),'P',P_hs,Fluid_System); %热源出口温度 s6(i) = refpropm('S','H',h6(i),'P',P_hs,Fluid_System); %热源出口熵值,J/(kg K) %% 有关冷却水的量 h7 = refpropm('H','T',T7,'P',101.4542,'Water'); %冷却水入口焓值,J/kg m_cw(i) = m3(i)*(h2-h3)/(h8-h7); %冷却水流量,kg/s h8(i) = h7+(m3(i)*(h2(i)-h3))/m_cw(i); %冷却水出口焓值,J/kg T8(i) = refpropm('T','H',h8(i),'P',101.4542,'Water'); %冷却水出口温度 W(i) = m3(i)*(h1(i)-h2(i)-h4(i)+h3); %净输出功,W efficiency(i) = W(i)/(m1*(h5-h6(i))); %热效率，- end %% 输出结果 plot(Te-273.15,efficiency,'d-'); %-d-p-o-s画图用 % xlswrite('data.xlsx',[Te'-273.15 W'/1000 efficiency*100]); %数据导出，℃，kW，%