The PRANA prognostic system identifies in advance the following types of defect and deviation of heat recovery steam generators:
- efficiency change (Tух);
- change of HP and LP steam parameters (temperature, pressure, steam capacity);
- amount of steam, condensate and feedwater (chemical parameters, cont. purging flow (regulated, must be 1% of rated steam flow maximum according to OM));
- change of HRSG aerodynamic resistance for in/out pressure (regulated, must be 3000 Pa maximum);
- change of drum level control quality;
- regularity of HP drum heating (based on regulated temperature difference between bottom and top parts – 60°C maximum);
- feedwater steam balance (indirect indicator of wear, wormholes, loss of tightness of heating surfaces).