turbulence flow

Temperature management in turbomachines is a critical factor for improving power plant efficiency and service life. Air gap clearances between combustion chamber rings assist its installation and expansion while partially modifying the inlet air path to stave off mixing in the flame tube of the combustion chamber. Changes in clearance dimensions can cause geometric asymmetry and result in asymmetric flow and temperature distribution imbalances in the combustion chambers creating hot spots at the outlet of the combustion chamber. Hence, in this paper, the effects of four clearance dimensions with four values on temperature distribution in two combustion chambers attached to the compressor have been numerically studied using Ansys Fluent 17. Taguchi method is applied for optimization and decreasing the outlet semi-circles temperature difference using Minitab software. The optimization results illustrate that the radial clearance between the flame tube and the mixing chamber is the most significant variable in controlling the air flow rate and producing symmetrical temperature distribution in the two chambers. So, one-millimeter radial clearance between two chambers leads to an increase of the temperature distribution by 15oC and 100oC in average and point mode, respectively. Also, results show that as the average clearance of the combustion chamber decreases by 5 millimeters, the point mode temperature of its corresponding outlet semi-circle decreases around 100°C.

Gas turbine inlet air is filtered in multiple steps. First, the filtration step is used for removing the big things. Then, Sand and dust are removed using the inertial sand separators. Sand separators filtration system is composed of 30 rows of the inertial sand separators on 5 floors. In this paper, one floor of the inertial sand separators filtration system of Shahid Kave power plant has been simulated using Ansys Fluent 16. A computational server with 20 processing cores and RAM of 120 GB was used to carry out the calculations. The velocity and pressure fields have been studied and the effect of density and diameter of particles on inertial sand separators efficiency are investigated. Particle diameter and density are varied between 0.1 to 100 micrometer and 500 to 2000 kg/m3 respectively. The result shows that the collection efficiency of the inertial sand separators was reduced by increasing the particle diameter. However, the collection efficiency of the inertial sand separators was improved by increasing the particle density. Also, a few particles are collected by inertial sand separators, so that collection efficiency is less than 1%. Therefore, this system is inefficient and not cost-effective and elimination of the system fans could reduce the energy consumption of the gas power plant around 360 kW.