Interaction effects of natural draft dry cooling tower (NDDCT) performance and 4E (energy, exergy, economic and environmental) analysis of steam power plant under different climatic conditions

摘要

The present study aimed to evaluate the interaction effects of Heller cooling tower performance and the energy, exergy, economic and environmental (4E) analysis of a unit of the shahid Montazeri steam power plant (SPP) in Iran by using the operational data of this power plant (PP), as well as the data from Heller cooling tower simulation. First, the evaluation process was performed in the ambient temperature (AT) of 16.1 degrees C and no cross crosswind blowing condition which the PP was designed. Then, the evaluation process was implemented in the other two modes of operation. The first mode is when the performance of the Heller cooling tower decreases due to minor changes in weather conditions (the increase of the AT and crosswind blowing) and consequently, the condenser vacuum pressure increases until it reaches the alarm vacuum pressure of the SPP. The second mode is when the condenser vacuum pressure has reached the alarm pressure, in which the condenser vacuum pressure is fixed at the alarm vacuum pressure of the SPP and the steam and fuel flow rates reduced to prevent the PP from tripping. The results indicated that the SPP generated power and the performance of cooling tower reached approximately 50% of its normal capacity in the worst climatic conditions causing 158800$ economic loss to SPP. Then it's observed that the effect of wind is greater than AT on the NDDCT and cycle performance. Also, the mechanism and magnitude of reducing SPP load capacity, mass fuel rate and cycle steam flow rate in different ambient condition were investigated.