Influence of cooling of high temperature vane systems on efficiency gas turbine units regarding working substance specific heat capacity dependence on temperature

Abstract

BACKGROUND: Gas turbine units (GTU) are widely used in power plants, shipbuilding, aerospace and other industry sectors. Main performance indicators of units are effective cycle efficiency and useful internal power. It is known that gas turbine power grows on 1525% for each 100C of turbine inlet temperature increases in range of 10001400 K, which makes it possible to save fuel significantly. Further growth of turbine inlet temperature demands more drastic increase of cooling air flow rate for the sake of cooling of the GTU flow channel, that leads to decrease of effective efficiency of a GTU. Consequently, the research of cooling and heat capacity properties influence needs to be done in order to improve gas turbine unit performance in the turbine inlet temperature range of 10001400 K.
 AIMS: Issues of influence of cooling of high temperature GTUs as well as issues of influence of working substance specific heat capacity dependence on temperature are studied in the article.
 METHODS: The study contains comparative analysis of four gas turbine units (GTU) such as: the 3,13 MW Teeda GTU (Iran), the 4,13 MW UEC Perm Engines GTU-4P (Russia), the 5,1 MW Siemens SGT-100 (Germany) and the 5,67 MW Solar Turbines TAURUS 60 (USA).
 RESULTS: As a result, dependencies of efficiency, specific effective work and GTU useful work coefficient on cooling were obtained. Working substance specific heat capacity dependence on temperature was considered in order to increase accuracy of calculations.
 CONCLUSIONS: The completed calculation study allows judging on perfection of the heat layout of GTU, the flow channel of GTU and making a comparison of them for the sake of further optimization of operational processes.