Research On Medium Automated Monitoring And Compensating Device In Foam Extinguishing System Of Oil Storage Vesselsin Oil Field

So far in common foam extinguishing systems for large scale oil depot,the existing foam proportioning units include in-line foam concentrate inducer,around-the-pump proportioner,balanced pressure proportioner,measured injection foam proportioner and pressure proportioner.The uncertainties still remain in actual use,such as the lag time of the response of water control,the hydraulic loss,the power-lossing of electronic control system and the faults of the foam proportioning units.The concentration of the foam solution made of foam concentrate and water is the key of extinguishing performance,it is affected by the factors discussed above.The foam extinguishing systems are open-loop control systems that there is no feedback between input terminal and output terminal.The disadvantage is its poor performance in both accuracy control and interference rejection.The variation of system parameters has a great influence on the system itself.Generally speaking,there are two major reasons.First,the output part at this stage is basically under the control of water conservancy machines,it's difficult to let the feedback act on the water conservancy machines then adjust high-precision output.Second,there's no product but only theoretical research on the monitoring of mixture ratio,so the collection of feedback signal remains to be developed.The main idea of this paper is to design a set of secondary monitoring device and compensation for the foam fire extinguishing system and the mixed foam liquid process in order to ensure the concentration of foam mixture.Device,on-line monitoring of pipe network foam concentration and other pipe network parameters,dynamic adjustment of electronic control valve to fill the foam liquid.Can be installed in each sub-tank area pipe network,the maximum compensation for the main network foam mixture concentration of zero,to ensure the reliability of fire fighting.Take pre-action start mode,in the event of fire within 30 seconds,the system will advance into the quasi-working state.The system provides three kinds of fault status and system operation status for the host computer,and uploads the information of four kinds of pipe network parameters to the host computer in order to provide the basis for the fire accident analysis.The main work of this paper includes:(1)the analysis of the uncertainties in foam proportioning units;(2)the analysis of the concentration of the foam solution and conductivity value;(3)the circuit design of the single chip computer technology;(4)C-based programming and the deduction for the control algorithm;(5)the simulation experiments of the system.