| The all-electric subsea production system has the advantages of rapid response,long control distance and environmental protection,which is the direction of submarine oil and gas field development.The all-electric subsea production control system is responsible for the power supply and operational status monitoring of the production facilities.It is the core of the all-electric subsea production system.Therefore,the research on the key technologies of the all-electric subsea production control system is of great significance to promote the development of Chinese deep-sea oil industry.The all-electric subsea production control system is mainly composed of three parts: the power transmission system,the electric subsea control module and the all-electric subsea valve actuator.Starting from the above three parts,the multi-module of series-parallel stacking combination is introduced to build its power conversion structure,an oil-filled cooling scheme for electric subsea control module was proposed,and the design and functional test verification of all-electric subsea valve actuator was completed.Based on the analysis of foreign subsea production systems,the design indicators are proposed.Based on the indicators,the architecture of the power transmission system is first completed,and then the mechanical structure design of the electric subsea control module and the all-electric subsea valve actuator is completed,and finally the design of the electronic control system is completed.In order to construct the power transmission system structure of the all-electric subsea production control system,the AC/DC transmission mode,voltage drop and power conversion mode are analyzed in detail.By comparing and analyzing the transmission efficiency,stability and laying cost of AC/DC transmission mode,the DC transmission mode is selected.By analyzing the influence of the supply voltage,load power and cable cross-sectional area on the long-distance transmission voltage drop of the long underwater cable,the optimal power supply scheme is obtained.Comparing and analyzing the voltage and current sharing characteristics of multi-module input series output series,input series output parallel by paralleling capacitors and input series output series-parallel interleaved topology,a power conversion method based on common duty ratio control strategy isproposed.According to the working mode of the all-electric subsea production control system and the structural characteristics of the electronic subsea module,the heat dissipation scheme of the electronic subsea module is proposed.An electronic subsea module heat source thermal resistance network is established,and the heat dissipation mechanism is analyzed accordingly.Based on the heat dissipation mechanism of the subsea electronic module,the oil immersed heat dissipation scheme is proposed,and the compensation method for the volumetric thermal expansion of the oil is designed.The finite element simulation analysis of the oil immersed cooling scheme is carried out to verify the feasibility of the selected scheme.According to the functional performance index of the all-electric subsea valve actuator,the overall structure and key structure design are completed.Through the analysis of the working principle of the all-electric subsea valve actuator,the opening,closing and fail-safe shut-off process are clarified.Through the simulation analysis of the action process of the wedge-shaped ram,it is found that the moment the ram opens or closes,the medium in the pipeline exerts the maximum force on the ram.Based on the working principle of the all-electric subsea valve actuator and the action of the wedge-shaped shutter,the design of the valve actuator return spring,the nut screw drive mechanism and the low-power retention mechanism is completed.In order to verify the output function of the all-electric subsea valve actuator and the fail-safe shut-off function,a test platform was built to perform functional test tests on the valve actuator. |
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