Page 362 - Defrosting for Air Source Heat Pump

358 Appendices

% density of gas at interface (saturation density), kg/m 3

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];
options=optimset(’display’,’off’,’MaxIter’,10000,
’MaxFunEvals’,20000); % number
[A,fval,exit]=fsolve(@(x)mystage41(x,kTw1,mr0,smvaw,i,
denspipe,dens_air,kTri,kRr,kMr,khri),x0,options);
mrw(j,i)=A(1); % retained water, kg/s
mvaw(j,i)=A(2); % vaporized 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
exit
2
hair(j,i)=1.4748.*Tri(j,1).^(1/3); % W/(m °C)
qair(j,i)=1.4748.*Tri(j,1).^(4/3).*2.6852*2.5*2; % W
s_qair(j,i)=sum(qair(:,i))*5; % W
2
hd(j,i)=hair(j,i)/1005./1.258./0.845^(2/3); % W/(m °C)
smvaw(j,i)=5.*sum(mvaw(:,i)); % kg
qm(j,i)=334000.*mf(j,i); % W
qvap(j,i)=mvaw(j,i)*2443*1000; % W
s_qvap(j,i)=sum(qvap(:,i))*5; % W
watertray(j,i)=0; % 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
end
end
end
% here is the end of stage 4 for Circuit 1: water layer evaporating
stage
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

for i=2
for j=18:45
% for the 18*5 seconds for the 2nd circuit;