Abstract:

Unlike conventional delayed coking, the design of the radiation feed pump in the new delayed coking technology needs to meet operating conditions such as low flow, high temperature and medium pressure, low viscosity, and variable pressure. The design and selection process has gone through two different types of centrifugal pumps, two different types of volumetric pumps, and then to the outlet control valve control scheme(valve control scheme) of small flow multi-stage centrifugal pumps. A beneficial exploration attempt was made on the design and selection of different types of pumps. Finally, the BB5 small flow multi-stage centrifugal pump was selected to be matched with the outlet regulating valve for the split pressure control scheme. After more than three years of industrial application, the pump operates smoothly, meets operating conditions, and all performance indicators meet design requirements. In addition, an alternative scheme using centrifugal pump variable frequency speed regulation was proposed and compared with the valve control scheme in terms of technology and economy. Compared with the valve control scheme, it is estimated that using the variable frequency speed regulation scheme can save a one-time investment of 150,000～180,000 yuan and save operating costs of 60,000 yuan per year.

Key words: small flow, radiation feed pump, design and type selection, low medium viscocity, BB5 multistage pump, non standard API pump, control valve control, variable frequency speed regulation

摘要：

与常规延迟焦化不同，新型延迟焦化技术中辐射进料泵的设计需满足小流量、高温中压、低黏度以及变压力等操作条件。设计选型过程经历了从两种不同类型离心泵到两种不同类型容积泵，再到小流量多级离心泵出口调节阀控制方案(阀控方案)的过渡。进行了不同类型泵设计选型的有益探索尝试，最后确定选用BB5型小流量多级离心泵配套出口调节阀分流分压控制方案。经三年多工业化应用，辐射进料泵运行平稳，满足操作条件，各项性能指标达到设计要求。此外，提出了采用离心泵变频调速的替代方案，并与阀控方案的经济性进行了对比。与阀控方案相比，预估采用变频调速方案可节约一次性投资15万元～18万元，节约操作费用6万元/a。

关键词: 小流量, 辐射进料泵, 设计选型, 低介质黏度, BB5型多级离心泵, API非标准泵型, 调节阀控制, 变频调速