An industrial gas turbine has the characteristic of decreasing output power on hot summer days while electricity demand peaks. Steam injection in gas turbines has been used for many years to prevent the loss of performance of gas turbines caused by high ambient temperature. Vodoley system is a Closed Steam Injection Gas Turbine Cycle (CSIGTC), which is known as a self-sufficient in steam production. In this study the influence of steam injection in Mashhad Power Plant GE-F5 gas turbine parameters was experimentally investigated. Moreover a computer modelling has been used to study water balance in a CSIGTC system. The results show that although system has additional water treatment process, applying it increases thermal efficiency up to 35.33 percents for 25 MW of power output at an ambient temperature of 40 ˚C. Also water balance considerations show for a direct contact condenser of 96% efficiency and the exhaust temperature of 420 ˚C at turbine outlet, about 7.8 kg/s of make up water is needed under ISO rating of gas turbine (101.3 kPa, 15 ˚C) which must be provided for the CSIGTC system. This amount of water is about 51% of injected steam. تفاصيل المقالة

In this paper the effect of block shape Vortex Generators (VGs) on an air-water fin-tube heat exchanger has been studied experimentally using exergy analysis method. Also the effect of these VGs on increasing heat transfer rate has been simulated numerically and the Results show a good agreement with the experiments. In this research we used a wind tunnel to produce wind flow over heat exchanger in the range of 0.054 kg/s to 0.069 kg/s. Hot water was circulating with the steady volume flow rate of 240 L/h and the temperature of 44 to 68 centigrade in the system. These experiments have been repeated with and without VGs on the heat exchanger. Results show using the VGs has reduced Air Side Irreversibility to Heat transfer Ratio (ASIHR). To reveal the effect of VGs on heat exchanger performance with respect to reducing ASIHR, a quantity is used namely Performance of Vortex Generator (PVG). The results represent that PVG values are in the range of less than 15% to over 35% which represents the good effects of VGs on the heat exchanger performance. تفاصيل المقالة