Steady-state simulation of the seawater greenhouse condenser

This paper presents an integrated steady-state model simulating the condenser of a seawater greenhouse in Oman. The developed model is capable of predicting the outlet air temperature and humidity, the outlet seawater temperature and the condensation rate. Validation experiments showed a good conformity between the predicted and measured values within the calibration ranges at high and low air flowrates. The mean predictive error (PE) for the predicted condensation rate was 15.25 and 22.67 mL min^-1 at high and low flowrates, respectively and the index of agreement (IA) was 0.96 and 0.98, respectively. The model also accurately predicted the outlet humidity ratio with PE values of –0.00006 and –0.00018 kg kg^-1 for high and low air flowrates, respectively and IA values of 1.00 and 0.99, respectively. The model showed a small discrepancy between the measured and predicted outlet air temperature but yet with a PE value of 0.35^oC and 2.44^oC at high and low air flowrates, respectively and IA values of 0.92 and 0.86, respectively. This discrepancy was attributed greatly to inaccuracy related to measurements caused by the non-horizontal airflow pattern and less-likely due to inaccuracy related to the simulation. The accuracy of the model to predict the outlet seawater temperature was excellent with a PE of –0.33^oC and –0.10^oC for high and low air flowrates, respectively and IA values of 0.98 and 0.99, respectively. Model’s accuracy was also evaluated using three additional statistical prediction indicators; coefficient of determination, mean absolute predictive error and root mean square error. It was found that all prediction indicators for high and low air flowrates were very good.