Novel lumped modeling for determining thermal performance of DX evaporator under partially-wet and fully-wet conditions

From the principles of heat and mass conservations, new mathematical correlation was created to predict the thermal behavior of direct-expansion (DX) evaporator coil under partially and fully-wet conditions. The main feature of this correlation is its simplicity and practice to be implemented. The new correlation interrelate the DX evaporator effectiveness (epsilon) with its number of transfer unit (NTU), and vice versa. The computational model was constructed on a basis of solving heat and mass transfer equation "enthalpy potential method" simultaneously coupled with the energy equations. The validity of the new correlations was tested by reference data reported in the available literature. In addition the comparison was conducted with the traditional numerical model. The output results of those correlations show satisfactory agreement with those obtained from the referenced data. Maximum deviation was 11.13%; however, most of the calculated errors were less than 10%. (C) 2015 Elsevier Ltd. All rights reserved.