Analysis of dynamic processes during the accidents in a district heating system

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.The accidents in the District Heating System are inevitable and they occur due to various reasons. Therefore it is necessary to perform the analysis of possible accident in piping system and to evaluate the consequences. After performing such analysis, it is possible to take the necessary measures to ensure safer and more reliable heat supply, so that the consequences of accidents are less severe. This paper demonstrated the capabilities of developed (using RELAP5 code) district heating network model for the analysis of dynamic processes. Three hypothetical accident scenarios in Kaunas city heating network are presented: (1) blackout in the Kaunas central part pump station; (2) break of heat supply pipe to northwestern district of Kaunas city; (3) rapid pump trip in one of Kaunas city pump stations. The discussion regarding dynamic processes (water hammer effect) in pipelines during the accidents is presented. The results of analysis demonstrated that the pressure pulsations as the accident consequences do not lead to the additional failures in pipelines in district heating system.