Design of a New Oil Cooling Lubricant Closed System for Gas Turbines in Gari (1, 2) Power Station

Abstract

The cooling lubrication oil of the turbine gas in GARI Thermal Station (1and 2) depends on the passage of the lubricating oil outside the tubes of the heat exchanger, and the cooling water from the cooling towers go to the inside of the pipes in the heat exchanger. It is an open system which makes the control of the treatment of the cooling water difficult. This system suffers from the effectiveness of the cooling because of the layer of lime salts building around the membrane tube, this layers is growing with time, and become as an insulator for heat exchange and cause the increment of the temperature of the lubricating oil, which affects the stability of the production of gas turbine. This research attempted to solve this cooling problem. It was done by examining the user's cooling system, and then changes the system to a new system. The new system is based on a closed system with treated cooling water to cool the lubricating oil. Then the treated water is cooled by the water coming from the cooling towers. This done by adding a flat heat exchanger, which was designed, and then was chosen from among a large number of thermal flat exchangers The lubricating oil entering at 70 ºC and leaves at 49 ºC and cooled by the treated water that enters at 33 ºC and leaves at 43 ºC. While the cooling water from the cooling towers at 31 ºC cooled the treated water and leaves at 32.5 ºC. The effectiveness of the new system was confirmed by using computational fluid dynamics program. The results show the consequences effective heat exchange between the lubricating oil and cooling water and matching the temperature degrees of the design heat exchanger. It was then worked out a model illustrates the new cooling system with full accessories. The cost of the production of the new system is found to be equivalent to the cast of loss of production due to gas turbine cooling system for a period of 9 days and 3 hours.