Theoretical analysis for HPHX's performance by using dimension analysis theory.
Assumptions
Steady operation conditions exist. The surface temperature of the condenser section is equal to the temperature of Refrigerant R-22.
Properties The exit temperature of air, and thus the mean temperature, is not known. We evaluate the air properties at the assumed mean temperature of 42OC (will be checked later) and 1 atm as following: K= 0.02722 (W/m.K) =1.1204 kg⁄m^3 C_p=1.007 kJ⁄(kg.K) Pr=0.71175 =0.00001924 kg⁄(m.s) 〖Pr〗_s=0.71819
Analysis It is given that D =0.00953 (m), S_L= S_T=0.0254 …show more content…
x C_p x (T_e-T_i )=0.1908 x 1007 x (42-36.71)=1016.42 W
Q_Latent=m x ΔX(Humidity ratio)
Q_Latent=400 x (1.574)*3.5 /12000=0.1836 Kw
Q_(Heat Recovered)=Q_Sensible+Q_Latent=1.01642+0.1836=1.20 Kw
The Efficiency of HPHX is ratio of actual heat transfer to the maximum possible heat transfer. Since HPHX involves recovery of only sensible heat, therefore the efficiency of HPHX can also be defined as ratio of actual temperature drop to maximum possible temperature drop. [51] ε_HPHX=(T_OA-T_LA)/(T_OA-T_RA )=(42-36.71)/(42-24) X 100%=29.38 %. Heat Pipe Heat Exchanger Design by using software selection programmes.
After we have finished our hand calculations as in above, now we will do the same calculation by using software which called SPC HPHR ( Version 2.5) from SPC company and Select Plus Design software (Version 1.1) from Hathway technology. we can calculate the volume, the dimension of the cooling coil, vertical heat pipe (number of rows, pressure drop, face velocity, heat pipe efficiency and heat recovery) by entering the values of both inlet and exhaust air characteristics and the suitable air flow Q.
By Using SPC HPHR (Version 2.5) from SPC company.
There are some parameters ( Input Data) to the selection programme as following
Assumptions
Steady operation conditions exist. The surface temperature of the condenser section is equal to the temperature of Refrigerant R-22.
Properties The exit temperature of air, and thus the mean temperature, is not known. We evaluate the air properties at the assumed mean temperature of 42OC (will be checked later) and 1 atm as following: K= 0.02722 (W/m.K) =1.1204 kg⁄m^3 C_p=1.007 kJ⁄(kg.K) Pr=0.71175 =0.00001924 kg⁄(m.s) 〖Pr〗_s=0.71819
Analysis It is given that D =0.00953 (m), S_L= S_T=0.0254 …show more content…
x C_p x (T_e-T_i )=0.1908 x 1007 x (42-36.71)=1016.42 W
Q_Latent=m x ΔX(Humidity ratio)
Q_Latent=400 x (1.574)*3.5 /12000=0.1836 Kw
Q_(Heat Recovered)=Q_Sensible+Q_Latent=1.01642+0.1836=1.20 Kw
The Efficiency of HPHX is ratio of actual heat transfer to the maximum possible heat transfer. Since HPHX involves recovery of only sensible heat, therefore the efficiency of HPHX can also be defined as ratio of actual temperature drop to maximum possible temperature drop. [51] ε_HPHX=(T_OA-T_LA)/(T_OA-T_RA )=(42-36.71)/(42-24) X 100%=29.38 %. Heat Pipe Heat Exchanger Design by using software selection programmes.
After we have finished our hand calculations as in above, now we will do the same calculation by using software which called SPC HPHR ( Version 2.5) from SPC company and Select Plus Design software (Version 1.1) from Hathway technology. we can calculate the volume, the dimension of the cooling coil, vertical heat pipe (number of rows, pressure drop, face velocity, heat pipe efficiency and heat recovery) by entering the values of both inlet and exhaust air characteristics and the suitable air flow Q.
By Using SPC HPHR (Version 2.5) from SPC company.
There are some parameters ( Input Data) to the selection programme as following