Analysis Of The Flow Field Of The Heavy Oil Pump Based On The Needs Of Liaohe Oilfield

As the world's energy crisis, every country begins growing interest in heavy oil exploitation. Currently the pumps used in heavy oil transportation have problems such as low efficiency, short maintenance cycle, high maintenance costs and environmental pollution. Therefore, the development of heavy oil pump with high efficient, energy-saving, environmental protection and durable has a huge economic and social benefits.In heavy oil transportation, the valve is the major factor for the reciprocating pump developing into high-power, high pressure and large volume. The optimization of valve is the main content of a reciprocating pump design. Traditional valve design and optimization are mainly based on the semi-empirical formula established in a one-flow theory and the engineering design manuals and diagrams, which causes great difficulties to the design and limits the improvement of product quality.In recent years, numerical simulation technique provides a new way to solve this problem. Through numerical simulation, we can not only achieve the required flow parameters and grasp the details of the internal flow field, but also shorten the design cycle and save the cost of experiments. This method effectively guided the valve design.For the fluid-solid coupling problem under action of the spring and fluid dynamics, the valve movement is extremely complex and can not be reflected in a simple way. In this paper, the relationships among the parameters such as the valve poppet's moving displacement, time, speed, acceleration and fluid dynamics are listed in the UDF(User Defined Functions) and combined with the CFD to simulate the valve poppet's unsteady opening and closing process. The structural parameters of the valve and the performance parameters of the pump are optimized from flow field analysis perspective. The reasonable auxiliary springs parameters are obtained by studying the impacts on the displacement and delay-closing time of the valve poppet. The best match between fluid viscosity and plunger velocity are obtained by simulation and analysis of flow field under different fluid viscosity.By testing the design model of the 7-cylinder reciprocating pump named 7KH-50-2.5, we can further validate the effectiveness of the design. The model pump can run smoothly without failure and leakage for week of continuous operation. Under the rated operating conditions, the pump efficiency is up to 89% and the volumetric efficiency is up to 94%. So we can conclude that the design pump can meet the conditions for heavy oil transport.