Study On VLEC Fire Prevention Measures In Construction Process Based On TRIZ

Under the background of increasing oil and gas production in shale and increasing supply of by-product ethane in the United States,a new type of liquefied gas carrier,Very Large Ethane Carrier(VLEC),is born for transporting ethane.In recent years,the major domestic shipyards have received a large number of VLEC construction orders,but the relevant construction experience is relatively deficient.In particular,the research on fire protection measures in the process of VLEC construction is still in its infancy.TRIZ is one of the most famous innovative design theories.It has a very complete theoretical system and a lot of practical methods to solve innovative problems.For many years,TRIZ has been widely used in the field of engineering technology,which is very effective in guiding and solving various practical problems.By means of suumarizing and analyzing typical fire accidents in the construction of liquefied gas carriers,the main causes of fire accidents in VLEC projects under construction has been found in the paper,where TRIZ has been used as an analysis method.Then these causes are transformed into the standard problem model of TRIZ,and the standard solution is obtained by using the corresponding Substance-Field analysis tool.Then,on the premise of combining with engineering practice,various fire prevention measures applied in the process of VLEC construction are studied and sumnarized.After that,in the course of the research on water spraying fire prevention measures,TRIZ has been further used as a method of solving physical contradictions in the innovative designing of water spraying tool in this paper.It solves a series of problems,such as tooling cannot be lifted,fixed without welding,limited construction space,and difficult operation of personnel.At last,FDS(fire dynamic simulator)software is used to simulate the fire accident and fire spread when the fire source is located at the top,middle and bottom of the cargo tank,with and without spray facilities.It can directly reflect the influence of spray coverage and fire location on fire hazard.That is to say,when the fire source is located in the spray coverage area on top of the cargo tank,the scheme can effectively control the occurrence of fire,and the increase speed of flue gas concentration is slow.When the fire source is located at the edge of the spray range in the middle of the cargo tank,the scheme can control the fire in a certain range and will not continue to expand,but the flue gas concentration rises rapidly.When the fire source is outside the spray range at the bottom of the eargo tank,the control effect of the scheme on the fire is limited,and the flue gas concentration rises rapidly.The fire simulation not only verifies the effectiveness of the design scheme of the water spray tooling,but also puts forward the fire hazard investigation and control at the bottom of the cargo tank during the construction of VLEC,increasing the water spray area with a larger angle nozzle,,and taking multiple fire prevention measures for the spray blind area.It can be used as a reference for fire prevention measures research and construction site safety management during the construction of VLEC,VLGC,LEG,LPG and other liquefied gas carriers in the future.