Page 360 - Defrosting for Air Source Heat Pump

356 Appendices

swatertray(j,i)=sum(watertray(:,i)); % kg
hro(j,i)=44518+1170.36*Tro(j,i)+1.68674*Tro(j,i)^2+5.2703/
1000*Tro(j,i)^3;
% kJ/kg
qr2(j,i)=kMr*(khri-hro(j,i)); % W
s_qr2(j,i)=sum(qr2(:,i))*5; % W

% here is the end of stage 2: frost melting without water flow to
down circuit
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
end
end
end
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

for i=1
for j=18:45
% for the 18*5 seconds for the 1st Circuit
kmw1=mf(j-1,i)+0.0192; % 0.0192 kg stands for the mass of
flowing water is the sum of the melting and the melted on the coil,
kg/s
ksmrw=sfrost(17,i); % the total mass of water retained on
the coil, the flowing part 0.0192 kg was neglected, kg
kTw1=Tw(j-1,i); %, °C
kTri=Tri(j,i); %, °C
2
kRr=Rr(j,i); % (K m )/W
kMr=Mr(j,i); % kg/s
khri=hri(j,i); % kJ/kg
% all the input parameters in the function listed here
x0=[0.0042 0.0042 0.335 1200 0.001]; % mf=x(1), mr=x(2),
Tw=x(3); qr=x(4); Tro=x(5) the values for debugging;
options=optimset(’display’,’off’,’MaxIter’,100000,
’MaxFunEvals’,20000); % number
[A,fval,exit]=fsolve(@(x)mystage31(x,kmw1,ksmrw,kTw1,i,
kTri,kRr,kMr,khri),x0,options);
mf(j,i)=A(1); % melted water, kg/s; after this stage, mf is 0 kg/s
mrw(j,i)=A(2); % retained water, kg/s
Tw(j,i)=A(3); % retained water temperature, °C
qr(j,i)=A(4); % energy used in defrosting from refrigerant, W
Tro(j,i)=A(5); % the temperature of tube surface at exit of
each circuit, °C

A
x00=real(A);
fval