Calculation of Water Delivery Time in Dry Pipe Sprinkler Systems
Julkaisun pysyvä osoite on
Kuivasprinklerjärjestelmän täyttymisajan laskentamenetelmä
An automatic ﬁre protection can be provided by a sprinkler system. The most common type of a sprinkler system is called a wet type system. A pipe network in the wet type systems is always ﬁlled with water and this type of a system can be used in spaces where the temperature remains in range where water occurs in liquid form. Dry pipe sprinkler systems are developed to be used in cold or hot conditions where wet type systems cannot be used. To prevent a sprinkler system from freezing, dry pipe systems are initially ﬁlled with pressurized gas and water is lead in after the system is activated. Before water can start to ﬁght against ﬁre, part of the gas has to be removed from the pipe network and water has to replace it. This gas removing and water ﬁlling phase weakens the fast response to the ignited ﬁre which is the best advantage of the automatic sprinkler systems. The scope of this thesis was to develope a calculation program that estimates the time that is consumed when part of the gas is removed from the sprinkler system and is replaced by water. The program was written in Python programming language. The motivation to develope this kind of a calculation program is to improve the designing procedure of the dry pipe sprinkler systems and to ensure that designed systems meet the restrictions of automatic sprinkler systems. The present practice in building design is to use a Building Infomation Modeling (BIM) programs. In this thesis the written program is developed to work with BIM program. The developed calculation program gets characteristics of the sprinkler pipe network from BIM program where the sprinkler pipe network is designed in three dimensions. From this information, the developed calculation program calculates an estimation of the time that is needed to remove part of the gas and to ﬁll the sprinkler pipe network with water, i.e. the time from system activation to real action of the system. The results of one example case were compared with the results of a commercial program. The results were satisfactory, which encourages to develope this program more for future use. Due to complex and only slightly limited pipe network conﬁgurations, interaction of two ﬂuid phases, and highly transient nature of the water ﬂow in the system, more testing is needed to verify the results and for further development of this calculation program.