This paper aims to study the minimizing of energy consumption in air cooled-heat exchanger through a convenient control system. Thus, the performance of a given air cooler has been considered in different weather conditions for both ideal and non ideal operations.
The minimum number of fans in service has been calculated and used for the study and assessment of a proper controlling system with the purpose of energy saving in air coolers. On-Off controlling has been compared to variable speed drivers controlling to determine a feasible method for the process control of this cooling equipment.
Economical parameters show that installing variable speed drivers could be rational, as the payback period, the net present values of investment and the internal rate of return are completely persuading. The internal rate of return (IRR) for installation of variable speed driver (VSD) controls is 69 per cent. According to the results, there is a possibility of 0.45 and 0.33 MWh energy consumption reduction for VSD control under ideal and non-ideal conditions and consequently reduces annually 318 and 237 ton equivalent CO2.
Air cooled heat exchangers are used as one of the energy consumption equipment in most plants, but before the emergence of serious problems, not enough attention was given to their operation.
