HTS Axial coil with cryocooler mass analysis

Calculate the coil and cryocooler mass for a magnet with a specific inner radius and target central field, as a function of operating temperature. This is also dependent on the amount of heat the cryocooler is removing, which is an input.

%--------------------------------------------------------------------------
% See also: CoilTurns, Cryocooler, PancakeMagnetMass, SuperPowerHTS
%--------------------------------------------------------------------------

%--------------------------------------------------------------------------
% Copyright Princeton Satellite Systems, 2019. All rights reserved.
% STTR NNX17CC74P
%--------------------------------------------------------------------------

% Optimal mass for a single high-temperature superconducting coil
% mirror coil: 15-20 T, inner radius 0.15 m
% axial coil: 5-7 T, inner radius 0.5 m

B0 = 2;      % T, largest center magnet is ~2 T
Ri = 0.45;   % m
qC = 5;      % W; a guess
nMag = 6;    % number of magnets

d = SuperconductorDataStructure('HTS');

Ts = linspace(10,69);
Zs = zeros(size(Ts));
Ns       = Zs;
massCoil = Zs;
massCryo = Zs;
Iop      = Zs;
for k = 1:length(Ts)
  Ic = SuperPowerHTS( B0, Ts(k) );
  Iop(k) = 0.6*Ic;
  N = 1;
  [massCoil(k),turns,height,width,N] = PancakeMagnetMass( B0, Ri, N, Iop(k), d );
  Ns(k) = N;
  if Ts(k)>50
    massCryo(k) = CryocoolerBrake( qC, Ts(k) );
  else
    massCryo(k) = CryocoolerBrake( qC, Ts(k) );
  end
end
mass = nMag*massCoil + massCryo;

% Compare to low-temp at 4 K
dLTS = SuperconductorDataStructure('LTS');
dLTS.Iop = 528;
[massCoilLTS,turnsL,heightL,widthL,Blts] = CoilTurns(Ri,1.5e6,dLTS);

% Cryocoolers
massCryoLTS = CryocoolerBrake( qC, 4.2 );

tStr = sprintf('HTS Coil and Cryo Mass, Qc = %g W',qC);
Plot2D(Ts,[massCoil;massCryo;mass],'Temperature','Mass',tStr)
[~,kMin] = min(mass);
hold on;
plot(Ts(kMin),mass(kMin),'k*')
plot(Ts(kMin),massCoil(kMin),'b.')
plot(Ts(kMin),massCryo(kMin),'r.')
legend('Coil','Cryo','Total','Min')

%plot([10 70],massCoilLTS*[1 1],'g--')


% an estimate of the structural mass (energy method), carbon fiber structure
rhoM   = 2500;    % Density (kg/m^3)
sigmaM = 1000e6; % Ultimate stress (N/m^2)
volume = 4/3*pi*Ri^3;
massStruct = MagnetMassVirial( rhoM, sigmaM, B0, volume );


if 0
disp('Use mouse to place text on plot')
gtext(sprintf('B0 = %g T, D = %g m',B0,2*Ri));
end


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Published with MATLAB® R2020a