Page 366 - Defrosting for Air Source Heat Pump

362 Appendices

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);%energyusedin defrosting fromrefrigerant.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
sfrost(j,i)=5.*sum(mf(:,i)); % after this stage, sfrost
(j,i)=0.350, kg
qair(j,i)=1.4748.*Tw(j,i).^(4/3).*2.6852*2.5*0.45*
((sfrost(j-1,i))./0.323).^1.5; % W
s_qair(j,i)=sum(qair(:,i))*5; % W
2
hair(j,i)=1.4748.*Tw(j,i).^(1/3); % W/(K m )
smvaw(j,i)=5.*sum(mvaw(:,i)); % kg
2
hd(j,i)=0; % W/(K m )
qvap(j,i)=mvaw(j,i)*2443*1000; % W
s_qvap(j,i)=sum(qvap(:,i))*5; % W
watertray(j,i)=kmw3; % kg/s
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 3 for Circuit 3: frost melting with water
flow to down circuit
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

if sfrost(j,i)>=0.35;
sfrost(j,i)=0.35; % kg
mf(j,i)=0; % 4th stage the mf is always 0, kg/s
kTw1=Tw(j-1,i); % the initial values are different for each
circuit, °C
mr0=0.008 ; % the water left on the first coil, kg/s
smvaw=smvaw(j-1,i); % at the beginning of this stage, it is 0, kg
% Coef7=-5800.2206;
% Coef8=1.3914993;
% Coef9=-0.04860239;
% Coef10=0.000041764768;
% Coef11=-0.000000014452093;
% Coef12=6.5459673;
Tair=0+273.15; % K; % Tair=0; % °C