我对MATLAB有疑问。我有类文件，我可以通过简单地在我的脚本中定义问题参数来解决我的问题，并在MATLAB中调用一个类来解决我提供的参数问题。现在，由类计算得到的变量，如何将它们导入到worskspace中或在我的MATLAB脚本中显示它们而不改变类？
班级代码
classdef rankine
% Rankine cycle class
properties
% Inlet properties
mass_flow; % Mass flow of system (kg/s)
Pboiler; % Boiler pressure (bar)
superheat; % Boiler degrees superheat (C)
isen_eff_turbine; % Turbine isentropic efficiency
Pcond; % Condenser pressure (bar)
subcooling; % Condenser subcooling
% Calclated properties
h_out_boiler; % Boiler outlet enthalpy (kJ/kg)
s_out_boiler; % Boiler outlet entropy (kJ/kg-K)
h_out_turbine; % Turbine outlet enthalpy (kJ/kg)
s_out_turbine; % Turbine outlet entropy (kJ/kg-K)
h_out_condenser; % Condenser outlet enthalpy (kJ/kg)
s_out_condenser; % Condenser outlet entropy (kJ/kg-K)
h_out_pump; % Pump outlet enthalpy (kJ/kg)
s_out_pump; % Pump outlet entropy (kJ/kg-K)
turbine_exh_quality; % Turbine exhaust quality
T_boiler_out; % Boiler outlet temperature (C)
T_turbine_out; % Turbine outlet temperature (C)
T_condenser_out; % Condenser outlet temperature (C)
T_pump_out; % Pump outlet temperature (C)
Q_boiler; % Boiler Heat Rate (kW)
W_turbine; % Turbine Work Rate (kW)
Q_condenser; % Condenser Heat Rate (kW)
W_pump; % Pump Work Rate (kW)
Q_net; % Plant Net Heat Rate (kW)
W_net; % Plant Net Work Rate (kW)
plant_efficiency; % Plant Thermal Efficiency
end
methods % Methods for rankine class
% Make constructor for the class
function obj=rankine(mass_flow,Pboiler,superheat,isen_eff_turbine,Pcond,subcooling)
% Enter system parameters
obj.mass_flow=mass_flow;
obj.Pboiler=Pboiler;
obj.superheat=superheat;
obj.isen_eff_turbine=isen_eff_turbine;
obj.Pcond=Pcond;
obj.subcooling=subcooling;
% Calculate boiler outlet specific enthalpy and entropy
if ~superheat % saturated vapor
obj.T_boiler_out=XSteam('Tsat_p',Pboiler);
obj.h_out_boiler=XSteam('hV_p',Pboiler);
obj.s_out_boiler=XSteam('sV_p',Pboiler);
else % Superheat
obj.T_boiler_out=XSteam('Tsat_p',Pboiler)+superheat;
obj.h_out_boiler=XSteam('h_pT',Pboiler,obj.T_boiler_out);
obj.s_out_boiler=XSteam('s_pT',Pboiler,obj.T_boiler_out);
end
% Calculate turbine parameters
h_out_s_turbine=XSteam('h_ps',Pcond,obj.s_out_boiler);
obj.h_out_turbine=obj.h_out_boiler-isen_eff_turbine*(obj.h_out_boiler-h_out_s_turbine);
obj.s_out_turbine=XSteam('s_ph',Pcond,obj.h_out_turbine);
obj.turbine_exh_quality=XSteam('x_ph',Pcond,obj.h_out_turbine);
obj.T_turbine_out=XSteam('Tsat_p',Pcond);
obj.W_turbine=mass_flow*(obj.h_out_boiler-obj.h_out_turbine);
% Calculate condenser parameters
if ~subcooling % saturated liquid
obj.h_out_condenser=XSteam('hL_p',Pcond);
obj.s_out_condenser=XSteam('sL_p',Pcond);
obj.T_condenser_out=obj.T_turbine_out;
v=XSteam('vL_p',Pcond);
else
obj.T_condenser_out=obj.T_turbine_out-subcooling;
obj.h_out_condenser=XSteam('h_pT',Pcond,obj.T_condenser_out);
obj.s_out_condenser=XSteam('s_pT',Pcond,obj.T_condenser_out);
v=XSteam('v_ph',Pcond,obj.h_out_condenser);
end
obj.Q_condenser=mass_flow*(obj.h_out_turbine-obj.h_out_condenser);
% Calculate pump parameters
obj.W_pump=(Pboiler-Pcond)*100*v*mass_flow;
obj.h_out_pump=obj.h_out_condenser+(Pboiler-Pcond)*100*v;
obj.s_out_pump=obj.s_out_condenser; % Isentropic case for now
%obj.s_out_pump=XSteam('s_ph',Pboiler,obj.h_out_pump);
obj.T_pump_out=XSteam('T_ph',Pboiler,obj.h_out_pump);
% Calculate boiler heat rate
obj.Q_boiler=(obj.h_out_boiler-obj.h_out_pump)*mass_flow;
% Calcualte net work and heat rates
obj.W_net=obj.W_turbine-obj.W_pump;
obj.Q_net=obj.Q_boiler-obj.Q_condenser;
obj.plant_efficiency=obj.W_net/obj.Q_boiler;
end % End constructor
function obj=update(obj,parameter_name,parameter_value)
switch lower(parameter_name)
case 'mass_flow'
obj.mass_flow=parameter_value;
case 'pboiler'
obj.Pboiler=parameter_value;
case 'superheat'
obj.superheat=parameter_value;
case 'isen_eff_turbine'
obj.isen_eff_turbine=parameter_value;
case 'pcond'
obj.Pcond=parameter_value;
case 'subcooling'
obj.subcooling=parameter_value;
otherwise
error('Parameter not modifiable. Parameters to modify are mass_flow, Pboiler, superheat, isen_eff_turbine, Pcond, subcooling')
end
% Calculate boiler outlet specific enthalpy and entropy
if ~obj.superheat % saturated vapor
obj.T_boiler_out=XSteam('Tsat_p',obj.Pboiler);
obj.h_out_boiler=XSteam('hV_p',obj.Pboiler);
obj.s_out_boiler=XSteam('sV_p',obj.Pboiler);
else % Superheat
obj.T_boiler_out=XSteam('Tsat_p',obj.Pboiler)+obj.superheat;
obj.h_out_boiler=XSteam('h_pT',obj.Pboiler,obj.T_boiler_out);
obj.s_out_boiler=XSteam('s_pT',obj.Pboiler,obj.T_boiler_out);
end
% Calculate turbine parameters
h_out_s_turbine=XSteam('h_ps',obj.Pcond,obj.s_out_boiler);
obj.h_out_turbine=obj.h_out_boiler-obj.isen_eff_turbine*(obj.h_out_boiler-h_out_s_turbine);
obj.s_out_turbine=XSteam('s_ph',obj.Pcond,obj.h_out_turbine);
obj.turbine_exh_quality=XSteam('x_ph',obj.Pcond,obj.h_out_turbine);
obj.T_turbine_out=XSteam('Tsat_p',obj.Pcond);
obj.W_turbine=obj.mass_flow*(obj.h_out_boiler-obj.h_out_turbine);
% Calculate condenser parameters
if ~obj.subcooling % saturated liquid
obj.h_out_condenser=XSteam('hL_p',obj.Pcond);
obj.s_out_condenser=XSteam('sL_p',obj.Pcond);
obj.T_condenser_out=obj.T_turbine_out;
v=XSteam('vL_p',obj.Pcond);
else
obj.T_condenser_out=obj.T_turbine_out-obj.subcooling;
obj.h_out_condenser=XSteam('h_pT',obj.Pcond,obj.T_condenser_out);
obj.s_out_condenser=XSteam('s_pT',obj.Pcond,obj.T_condenser_out);
v=XSteam('v_ph',obj.Pcond,obj.h_out_condenser);
end
obj.Q_condenser=obj.mass_flow*(obj.h_out_turbine-obj.h_out_condenser);
% Calculate pump parameters
obj.W_pump=(obj.Pboiler-obj.Pcond)*100*v*obj.mass_flow;
obj.h_out_pump=obj.h_out_condenser+(obj.Pboiler-obj.Pcond)*100*v;
obj.s_out_pump=XSteam('s_ph',obj.Pboiler,obj.h_out_pump);
obj.T_pump_out=XSteam('T_ph',obj.Pboiler,obj.h_out_pump);
% Calculate boiler heat rate
obj.Q_boiler=(obj.h_out_boiler-obj.h_out_pump)*obj.mass_flow;
% Calcualte net work and heat rates
obj.W_net=obj.W_turbine-obj.W_pump;
obj.Q_net=obj.Q_boiler-obj.Q_condenser;
obj.plant_efficiency=obj.W_net/obj.Q_boiler;
end % End update
function plot_ts(obj) % Plots the t-s diagram of the process
% Get the minimum and maximum pressures and temperatures
Tmax=obj.T_boiler_out;
Pmax=obj.Pboiler;
Pmin=obj.Pcond;
ts_diagram([Pmin Pmax],Tmax*1.5);
title('T-s Diagram For Process')
axesHandles=get(gcf,'Children');
classHandles=handle(axesHandles);
axes(classHandles(1))
hold on
% First draw the turbine process
plot([obj.s_out_boiler obj.s_out_turbine],[obj.T_boiler_out obj.T_turbine_out],...
'Linewidth',3,'Color','k')
% Draw the condenser process
sL=XSteam('sL_p',obj.Pcond); % Saturated liquid entropy
s_line=[obj.s_out_turbine sL];
T_line=[obj.T_turbine_out obj.T_turbine_out];
if (obj.subcooling~=0) % Subcooled
s_line=[s_line obj.s_out_condenser];
T_line=[T_line obj.T_condenser_out];
end
plot(s_line,T_line,'Linewidth',3)
% Draw the pump process
s_line=[obj.s_out_condenser obj.s_out_pump];
T_line=[obj.T_condenser_out obj.T_pump_out];
plot(s_line,T_line,'Linewidth',3,'Color',[0.5 0 0.5])
% Draw the boiler process
sL=XSteam('sL_p',obj.Pboiler);
s_subcooled=linspace(obj.s_out_pump,sL,101);
T_subcooled=arrayfun(@(s) XSteam('T_ps',obj.Pboiler,s), s_subcooled);
sV=XSteam('sV_p',obj.Pboiler);
TV=XSteam('Tsat_p',obj.Pboiler);
s_line=[s_subcooled sV];
T_line=[T_subcooled TV];
if (obj.superheat>0)
s_super=linspace(sV,obj.s_out_boiler,101);
T_super=arrayfun(@(s) XSteam('T_ps',obj.Pboiler,s), s_super);
s_line=[s_line s_super(2:end)];
T_line=[T_line T_super(2:end)];
end
plot(s_line,T_line,'Linewidth',3,'Color','r')
LH=legend('Turbine','Condenser','Pump','Boiler','Location','northwest');
set(LH,'Color','w')
end % End plot_ts
function plot_mollier(obj)
% Get extremities of operating points
Phigh=obj.Pboiler;
Plow=obj.Pcond;
slow=obj.s_out_condenser;
shigh=obj.s_out_boiler;
hlow=obj.h_out_condenser;
hhigh=obj.h_out_boiler;
x_exhaust=obj.turbine_exh_quality;
Thigh=obj.T_boiler_out;
T_low=XSteam('T_ps',Phigh,shigh);
pressures=[Plow/2 Plow Plow/4+Phigh/8 Plow/2+Phigh/4 Phigh/2 Phigh Phigh*1.5];
temperatures=[Thigh-rem(Thigh,10)+10];
entropies=[slow*0.8 shigh*1.2];
qualities=min([0.7 x_exhaust-rem(x_exhaust,0.05)-0.05]):0.01:1;
hrange=[hlow*0.8 hhigh*1.2];
mollier(entropies,hrange,pressures,temperatures,qualities);
title('Mollier diagram for process')
axesHandles=get(gcf,'Children');
classHandles=handle(axesHandles);
axes(classHandles(1))
hold on
% Plot turbine line
plot([obj.s_out_boiler obj.s_out_turbine],...
[obj.h_out_boiler obj.h_out_turbine],...
'Linewidth',3,'Color','k')
% Plot condenser line
scond=linspace(obj.s_out_turbine,obj.s_out_condenser,101);
hcond=arrayfun(@(s) XSteam('h_ps',obj.Pcond,s),scond);
plot(scond,hcond,'Linewidth',3,'Color','b')
% Plot pump line
spump=[obj.s_out_condenser obj.s_out_pump];
hpump=[obj.h_out_condenser obj.h_out_pump];
plot(spump,hpump,'Linewidth',3,'Color',[0.5 0 0.5])
% Plot boiler line
sboiler=linspace(obj.s_out_pump,obj.s_out_boiler,101);
hboiler=arrayfun(@(s) XSteam('h_ps',obj.Pboiler,s),sboiler);
plot(sboiler,hboiler,'Linewidth',3,'Color','r')
LH=legend('Turbine','Condenser','Pump','Boiler','Location','northwest');
set(LH,'Color','w')
end % end plot_mollier
end % End Methods
end % End rankine class
我的脚本调用它。
clc;
clear all;
close all;
import rankine
%Problem 1
mass_flow = 200;
Pboiler = 50;
superheat = 0;
isen_eff_turbine = 0.85;
Pcond = 1;
subcooling = 5;
problem1 = rankine(mass_flow, Pboiler, superheat, isen_eff_turbine, Pcond, subcooling)
Rankine类为每个步骤输出解决方案，例如
h_out_boiler
s_out_boiler
h_out_turbine
s_out_turbine
基本上，我想把Rankine类输出的变量放到MATLAB工作区而不修改rankine类。 感谢。
答案 0 :(得分：2)
将以下内容添加到您的脚本中：
rankineOutput = struct(problem1) ; %// convert the object into a structure
fldNames = fieldnames(rankineOutput) ; %// get the field names of the structure
for iField = 1:numel(fldNames)
varName = fldNames{iField} ; %// extract specific field name (just for the sake of clarity)
assignin('base', varName , rankineOutput.(varName) ) ; %// assign the value in the field to a variable with the same name in the base workspace
end
您可能会收到关于将对象转换为结构的警告，但您可以忽略它（它不会更改类的实现）。
这会将所有字段提取到基础工作区中的变量中。如果您只想要一个子集，则可以使用相同的方法，但在提取的字段中更具选择性。
取决于您的Matlab版本，您甚至可以通过直接在对象上调用它来避免转换为结构：
fldNames = fieldnames(problem1) ; %// get the field names of the object
for iField = 1:numel(fldNames)
varName = fldNames{iField} ; %// extract specific field name (just for the sake of clarity)
assignin('base', varName , problem1.(varName) ) ; %// assign the value in the field to a variable with the same name in the base workspace
end
答案 1 :(得分：1)
假设类构造函数是rankine(...)并且被称为rankine.m。将文件放入Matlab目录。然后，使用以下行来实例化它。
problem1 = rankine(mass_flow, Pboiler, superheat, isen_eff_turbine, Pcond, subcooling)
在该行之后，对象problem1现在位于您的工作区中。由于属性是公共属性，因此您可以使用.运算符直接访问它们。您也可以使用其他属性执行此操作。
problem1.h_out_boiler
problem1.s_out_boiler
problem1.h_out_turbine
problem1.s_out_turbine