1Mechanical Engineering Department, C. K. Pithawalla College of Engineering and Technology, Surat - 395007, India.
2Mechanical Engineering Department, S. V. National Institute of Technology, Surat - 395007, India.
The development of the combustion chamber for 20kw gas turbine unit using kerosene type fuel has been undertaken keeping in view the basic requirements of a good combustion chamber, namely, high combustion efficiency, low pressure loss, smooth ignition, wide stability limits, size and shape compatible with engine envelop, low emissions of smoke, unburned fuel and gaseous pollutant species, durability and ease of maintenance. A sophisticated experimental test rig has then been developed to investigate over a wide range of air/fuel ratios for the temperature profiles at the few radial and axial locations of this combustion chamber and pressure distribution along the length of combustion chamber. The different combustion chambers were designed at different equivalence ratios ranging from 0.5 to 1.1. The range of overall air/fuel ratios considered varies from 22.74 to 152.4 i.e. Rich Fuel Mixture to Lean Fuel Mixture Range. The temperature profiles for centerline, liner wall and exit gas temperature for four different air/fuel ratios are summarized here. It is worth to mention that the temperatures of near 1400°C achieved at the centerline of the combustion chamber and the liner wall temperatures in the range of 500°C for lower air/fuel ratio and 300°C for higher air/fuel ratio certainly ensures safe and reliable operation of this combustion chamber. The pressure distribution across the combustion chamber is studied using 14 U tube manometers. The highest pressure drop witnessed along the length of combustion chamber is 6% of the delivery pressure. This suggests the superiority in the aerodynamic design perspective of the combustion chamber. It is concluded that an equivalence ratio of 0.9 gives the consistent centerline temperature; lower liner wall temperature and uniform exhaust gas temperature.
