Page 359 - Defrosting for Air Source Heat Pump

Appendices 355

hro(j,i)=44518+1170.36*Tro(j,i)+1.68674*Tro(j,i)^2+5.2703/
1000*Tro(j,i)^3;
qr2(j,i)=kMr*(khri-hro(j,i)); % W
s_qr2(j,i)=sum(qr2(:,i))*5; % W
% here is the end of stage 1: preheating stage
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

else if j>=8
khri=hri(j,i); % kJ/kg
kMr=Mr(j,i); % kg/s
kTri=Tri(j,i); % °C
2
kRr=Rr(j,i); % (K˙m )/W
ksmrw=sfrost(j-1,i); % the total retained water on 5*j
seconds, kg
kTw1=Tw(j-1,i); % the temperature of the melted frost on
5*j seconds, °C
% all the input parameters in the function listed here
x0=[0.0034 0.0034 0.35 1200 0.001]; % mf=x(1), mrw=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)mystage2(x,ksmrw,kTw1,i,kRr,
kTri,khri,kMr),x0,options); % kRr1, kTr1 % uw(j,i)=A(1);
mf(j,i)=A(1); % the mass of melted frost, kg/s
mrw(j,i)=A(2); % the mass of retained water, kg/s
Tw(j,i)=A(3); % the temperature of retained water, °C
qr(j,i)=A(4); % the energy used in defrosting from refrig-
erant, W
Tro(j,i)=A(5); % the temperature of tube surface at exit
of each circuit, °C
A
x00=real(A);
fval
exit
qm(j,i)=334000.*mf(j,i); % W
effq(j,i)=qm(j,i)/qr(j,i); % 1
sfrost(j,i)=5.*sum(mf(:,i)); % kg
mvaw(j,i)=0; % kg/s
smvaw(j,i)=5.*sum(mvaw(:,i)); % kg
2
hair(j,i)=0; % W/(m °C)
qair(j,i)=0; % W
s_qair(j,i)=sum(qair(:,i))*5; % W
2
hd(j,i)=0; % W/(m °C)
qvap(j,i)=mvaw(j,i)*2443*1000; % W
s_qvap(j,i)=sum(qvap(:,i))*5; % W
watertray(j,i)=0; % kg/s