Simscape model of latent heat storage in a PCM

66 次查看（过去 30 天）
Hans Eichel
Hans Eichel 2016-8-25
回答： Vaishak 2024-10-23
Dear fellows,
I'm struggeling to model a latent heat storage component in Simscape for phase change materials (PCM). Hope you have ideas how to takle the problem.
Goal:
Simple PCM model that neglects the volume change, pressure increase or material flux. The only variables shall be the Simscape accross and through variables heat flow q in [J/s] and T in [K]. The parameters shall be:
  • Cps... specific heat in solid state [J/(kg K)]
  • Cpl... specific heat in liquid state [J/(kg K)]
  • m... Mass of PCM material in [kg]
  • Tmelt...Melting Temperature of PCM [K]
  • L... Specific latent heat in [J/kg]
What I have:
In the change from solid to liquid, the storred energy increases strongly. For the concept, have a look at the PhD Thesis of Simone Arena.
The Formula for the storred heat energy in [J] is:
Q(T=0 to Tmelt) = m * integral(Cps dT,0,Tmelt)
Q(T=Tmelt) = m * L
Q(T=Tmelt to Inf) = m * integral(Cpl dT, Tmelt, Inf)
How would you define the branches and equations for simscape for the heat flow q = dQ/dt?
Thank you so much!
  2 个评论
beta317
beta317 2018-3-25
The problem that you are describing is exactly the same problem that I am facing at the moment. Did you find a way to model a latent heat storage component in Simscape for phase change materials (PCM) and how did you accomplish that?
Thanks in advance for your help!
Anubhav
Anubhav 2022-7-22
This code is not working, can anyone elaborate in simulink

请先登录，再进行评论。

请先登录，再回答此问题。

回答（3 个）

Andrew Schenk
Andrew Schenk 2016-9-21
It seems this block would be very similar to the Simscape thermal mass block. You can see the Simscape source for this block by running this command:
>> edit foundation.thermal.elements.mass
In the thermal mass block, there is only one equation which defines Q. Based upon the equations you provided, you would modify the single heat flow equation to instead be:
if T < Tmelt
Q == m * integral(Cps dT,0,Tmelt)
else if T > Tmelt
Q == m * integral(Cpl dT, Tmelt, Inf)
else
Q == m*L;
end
It would be numerically preferable to reformulate the equations to use the Simscape der() operator instead of integ().
  4 个评论
显示 2更早的评论
Vishnubharathi thirupathi
Vishnubharathi thirupathi 2019-9-29
Did you find the answer? How did you finally get to implement PCM block?
Anubhav
Anubhav 2022-7-22
pls solve this in simulink because it is not working there

请先登录，再进行评论。

Vaishak
Vaishak 2024-2-21
This code maybe useful:
component PCM_NEW
% Two-port thermal component
nodes
M = foundation.thermal.thermal; % :top
end
nodes(ExternalAccess = none)
N = foundation.thermal.thermal; % :bottom
end
parameters
mass = {1, 'kg'}; % Mass
end
parameters
sp_heat = {4186, 'J/(kg*K)'}; % Specific heat
end
parameters
la_heat = {336000, 'J/kg'}; % Latent heat
end
parameters
T_melt = {273, 'K'}; % Melting Temperature
end
parameters (ExternalAccess = none)
diff = {1, 'K'}; % Mass
end
parameters
Intial_f = {1, '1'}; % Initial fraction of solid (0 to 1)
end
parameters
num_ports = foundation.enum.numPorts2.one; % Number of graphical ports
end
if num_ports == 2
annotations
N : ExternalAccess=modify
end
end
variables
% Differential variables
T = {value = {300, 'K'}, priority = priority.high}; % Temperature
Q = {0, 'W'}; % Heat flow rate
f= {1, '1'}; % Initial fraction of solid (0 to 1)
end
branches
Q : M.Q -> *;
end
equations
assert(sp_heat > 0)
assert(la_heat > 0)
assert(T_melt > 0, 'Temperature must be greater than absolute zero')
assert(T > 0, 'Temperature must be greater than absolute zero')
T == M.T;
end
equations(Initial=true)
f==Intial_f;
end
equations
if Q>=0
if f>=1 && T<(T_melt-diff)
Q==mass*sp_heat*T.der
f.der==0;
elseif f<=0 && T>(T_melt+diff)
Q==mass*sp_heat*T.der
f.der==0;
else
if f<0
Q==mass*sp_heat*T.der
f.der==0
else
Q==-mass*la_heat*f.der
T.der==0;
end
end
else
if f>=1 && T<(T_melt-diff)
Q==mass*sp_heat*T.der
f.der==0;
elseif f<=0 && T>(T_melt+diff)
Q==mass*sp_heat*T.der
f.der==0;
else
if f>1
Q==mass*sp_heat*T.der
f.der==0
else
Q==-mass*la_heat*f.der
T.der==0;
end
end
end
end
connections
connect(M,N)
end
end
Vaishak
Vaishak 2024-10-23
The above code can be used through a simscape component
https://www.mathworks.com/help/simscape/ref/simscapecomponent.html

类别

在 Help Center 和 File Exchange 中查找有关 General Applications 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by