Research And Design Of The Key Parts On The Sprinkler-foam System

With the rapid development of social economy, the basic development trend ofconstruction is to develop in the direction of multipurpose, multifunction, composite.Nowadays, large-scale integrated building contains many functions, such as largeunderground parking garage, large warehouses, oil depot, diesel generator room andfuel boiler room, etc. These buildings contain both large number of combustible solid,and store large amounts of flammable liquid. The current widespread use of medium ofautomatic sprinkler system is water. For fire disaster caused by combustible solid (classA fire), water can have a very good effect. However, for fire caused by combustibleliquid (class B fire), fire water is difficult to exert its function. Foam extinguishing has agreat advantage for class B fire.Therefore, this article combines the enormous strength of the foam fire-fighting tomake up for the shortage of automatic sprinkler system and make a deep research andtest on the sprinkler-foam System. This combined system integrates effects of water andfoam fire extinguishing, which saves water and reduces the cost, so it is an efficient andeconomic system.This paper designs a new type of automatic sprinkler-foam extinguishing system.According to the analysis of the existed automatic sprinkler-foam extinguishingsystem, it is concluded that the existed combination system of foam liquid mixing ratiois not accurate, time duration of continuous foaming agent is short, foam power supplyis weak, power supply is single. Through the analysis of the existed automatic sprinkler,type selection of the wet sprinkler device is determined. By analyzing the advantagesand disadvantages of existing foam proportional mixing device, and determine the foamproportional mixing device type selection, this design selects the balance type foamproportional mixing device. According to the foam proportional mixing device selection,combined with wet automatic sprinkler system, preliminary structure of the system is made.For class A and class B fire may exist in large comprehensive buildings, this articleanalyzed the existed automatic sprinkler and foam proportional mixing device anddesigned a new kind of automatic sprinkler-foam extinguishing system. In this papertwo subsystems’ design, selection and tests have been carried out respectively andanalyze the test data to verify its reasonability. To summarize the full text, this thesismainly do the following several aspects:(1) Design a new type of automatic sprinkler-foam extinguishing system.According to the analysis of the existed automatic sprinkler-foam extinguishingsystem, it is concluded that the existed combination system of foam liquid mixing ratiois not accurate, time duration of continuous foaming agent is short, foam power supplyis weak, power supply is single. Through the analysis of the existed automatic sprinkler,type selection of the wet sprinkler device is determined. By analyzing the advantagesand disadvantages of existing foam proportional mixing device, and determine the foamproportional mixing device type selection, this design selects the balance type foamproportional mixing device. According to the foam proportional mixing device selection,combined with wet automatic sprinkler system, preliminary structure of the system ismade.(2) Design a set of wet alarm valve group, the rated maximum working pressure is1.2MPa, nominal diameter of the wet alarm valve is DN150mm. According to theexisted advanced principle of the wet automatic sprinkler, through hydrauliccalculation, the factors that affect the pipe pressure loss, flow velocity, flow of the firewater have been determined, and determine the parameter selection of the keycomponents.(3) According to the requirements of the national standard GB5135.2-2003《Automatic Sprinkler System》, we have done a lot of work for wet sprinkler valvegroup in this paper, such as the prototype production, installation of test system and test,including the valve body strength test, hydraulic friction test and alarm test, alarm testincludes alarm flow, pressure, time delay and pressure ratio test. The analysis ofexperimental data shows that the wet type automatic sprinkler system design isreasonable, which meets the design requirements.(4) The project designed a set of hybrid balance type foam proportional mixingdevice. Firstly, the paper determined a diesel-electric hybrid model of foam drive by means of functional design; Secondly through the establishment of the mathematicalprinciple of bubble mixed and balance equation, the theoretical feasibility of thesubsystem has been determined, and the general structure of the device has beendesigned; Finally the device parameter has been designed and the key parts have beenselected.(5) According to the national standard GB20031-2005《The Foam ExtinguishingSystem and Parts General Technical Conditions》, we have done a lot of work for foamproportional mixing device in the paper, such as prototype production, the installation ofthe test system and test. First of all, inlet and outlet pressure loss of the proportioningmixer has been tested. Then the mixing ratio has been tested, which includes water testand bubble test.