Research On Design Technology Of Deep-water Piston-type Pressure-compensated Accumulator

The accumulator is an important auxiliary power source for the subsea oil production control system.When applied to deep water,conventional accumulators face problems such as reduced efficiency and excessive internal pressure.This paper studies the accumulators used in deepwater control systems.Firstly,this paper investigates and studies the era background of deepwater oil recovery,calculates the working efficiency of the conventional accumulator when it is used in deep water,and explains its problems.Combined with the requirements of the deepwater control system for the accumulator,a new type of piston pressure compensation accumulator was designed.The analysis shows the working principle of the piston type pressure compensation accumulator.Through analysis of the force of the piston,it shows that the realization of the function of the pressure compensation accumulator requires a specific size.Then,according to the standard,the cylinder block,end cap and chamber of the piston pressure compensation accumulator were designed and checked,and the force of the cylinder was analyzed through finite element to illustrate the feasibility of the design results.According to the working conditions of the accumulator,the importance of sealing is explained.The static seal and dynamic seal of the accumulator were studied in two aspects.In terms of static sealing,through simulation and analysis,the effect of the sealing gap,compression amount,and oil pressure of the conventional O-ring and retaining ring seal on the sealing performance and the force of the seal ring was obtained.The working condition of the deepwater piston pressure compensation accumulator was comprehensively analyzed.The dumbbell-type seal ring and the conventional O-ring were analyzed and compared,indicating that the dumbbell-shaped seal ring is more suitable for the static seal of this design.In terms of dynamic sealing,according to the law of the movement of the piston,a right angle slip ring type combined seal and a C-shaped slip ring type combined seal used between different chambers was studied.The effects of seal clearance,piston speed,and compression on seal performance and O-ring stress were analyzed.Piston pressure compensation accumulators have been chosen to guide the selection of suitable sealing structures for different operating conditions.Through this design and research,the problems faced by conventional accumulators in deepwater are pointed out,and a piston-type pressure compensation accumulator is proposed.From the aspect of the force of the piston,the superiority of its application to deep water is explained.The force of the cylinder was analyzed and the seal of the accumulator was studied.It solves the problem for the realization of piston pressure compensation accumulator function,and provides certain ideas and guidance for the design of accumulator in different situations.