Study On Key Problems In The Design Of The Fire Pump System

The fire pump system is an important part of the fire extinguishing system.In the current code of fire protection,there are only some provisions and requirements for the performance parameters of fire pumps and their control methods,and most of the references at home and abroad are about analysis and innovation for a certain function.There is a lack of research on the impact or correlation between the fire pump system and its surrounding individuals and the whole.In this paper,the key problems in the design of the fire pump system are studied.According to the running process of the fire pump system,the main contents and achievements of this paper are as follows:1.This paper analyses the difference between the recommended data of the code and the actual calculation design parameters,especially the fire hydrant system in a high-rise building,it will affect the water pressure of high-rise when the fire hydrants in both high-rise and low-rise attention to when selecting pumps so that requirements of flow and head of the fire pump system when running can be met.2.The head loss of the fold in the tap belt is analyzed and calculated,and the total resistance coefficient is determined by introducing "the local resistance adjacent influence coefficient".Under the conditions of certain fire hydrant orifice pressure,the forces of the fire hose and its intermal water body are analyzed.The ellipse parameters of the section,head loss and flow rate of the hose are calculated and solved by iteration method.The influence of water pressure on the section shape,head loss per unit length and flow rate of the fire hose is analyzed.3.Fire pump selection,standbextinguish fire at the same time,and the key problems are put forward that should be paid y pump configuration and multi-pump combination.Pumps with lower specific speed should be preferred,and fire pump units should be set up separately when the water consumption of different systems in large and medium-sized buildings is quitedifferent.Multi-stage and multi-outlet pumps are suitable for multi-outlet fire water supply with little difference in water consumption and non-simultaneous fire water supply at multiple outlets.It is more important to set up a standby pump for fire main pumps than a standby pump for pressure stabilized pumps.The optimum combination scheme of multi-pump combination and the pressure stabilized pump system is determined by "Comparing annual comprehensive price method".4.Optimization analysis of suction pipes and water supply pipes.In order to make the NPSH of fire pumps always larger than the NPSH r of pumps,the suction pipes should not only be designed according to the norms and routines,but also,we should fully understand the characteristics of pipes and valves to reduce head losses.The "calculation method of price comparison difference" is used to determine the connection mode between water supply pipes and networks.The key points of pipe layout are summarized to reduce maintenance difficulty and ensure the safety of the system.5.From three aspects of environmental requirements,control modes and maintenance management,the requirements are put forward to ensure the reliability of the fire pump system operation.The temperature of fire pool should not be too low(anti-icing),the ambient temperature of fire control cabinet should not be too high(not more than 30?),the ambient humidity should not be too high(anti-condensation);The button beside the hydrant should be able to start the pump directly;the maintenance and management should have feasible institutional guarantee,and remote monitoring using Internet technology.The safety and reliability of the fire pump system should be ensured definitely.6.The development trend of the fire pump system is discussed.The miniaturized fire pump system and the automatic fire extinguishing system are widely used.The design of fire water system for super high-rise buildings is as safe and reliable as possible by using normal high pressure(such as elevated pool).The Internet technology,intelligent technology,remote monitoring are used in fire pump system management.The conclusions and results of this paper can provide reference for the design,operation,maintenance and modification of the fire pump system and the revision of relevant standards and norms.