Flow Loss Analysis and Optimal Design of a Diving Tubular Pump

Abstract

As important parts of underground water conveyance equipment, diving tubular pumps are widely used in various fields related to the national economy. Research and development of submersible pumps with better performance have become green goals that need to be achieved urgently in low-carbon development. This paper provides an effective approach for the enhancement of the performance of a diving tubular pump by adopting computational fluid dynamics, one-dimensional theory, and response surface methodology. First, the flow loss characteristics of the pump under several flow rate conditions are analyzed by entropy production theory, and then the impeller and guide vanes are redesigned using the traditional one-dimensional theory. Then, the surface response experimental method is used to improve pump hydraulic efficiency. The streamline angle (A) of the front cover of the impeller blade, the placement angle (B) of the middle streamline inlet, and the placement angle (C) of the rear cover flowline inlet are the response variables to optimize the design parameters of the diving tubular pump. Results show that wall entropy production and turbulent kinetic energy entropy production play the leading role in the internal flow loss of the diving tubular pump, while viscous entropy production can be ignored. The flow loss inside the impeller is mainly concentrated at the inlet and the outlet of the impeller blade, and the flow loss inside the guide vane is mainly concentrated in the area near the guide vane and the entrance of the guide vane. A, B, and C are all significant factors that affect efficiency. The order of the influencing factors from strong to weak is as follows: A2 (p = 0.000) > C (p = 0.007) = A × B (p = 0.007) > B (p = 0.023) > B2 (p = 0.066) > A× C (p =0.094) > A (p = 0.162) > C2 (p = 0.386) > A×B (p =0.421). The best combination of response variables after surface response test design is A = 9°, B = 31°, and C = 36°. After optimization, the pump efficiency and the head of the model pump are increased by 32.99% and 18.71%, respectively, under the design flow rate. The optimized model pump is subjected to tests, and the test data and the simulation data are in good agreement, which proves the feasibility of using the surface response method to optimize the design of the model pump.

Analysis and Verification of Airborne Instrument Electromagnetic Emission Test

“…If the shell of the filter is not lapped with the low impedance of the product housing, the common-mode filter capacitor is equivalent to being connected with the housing after passing through the high impedance inductance and cannot play the role of filtering. Its equivalent antenna is a monopole antenna and radiates externally [9] . The equivalent antenna with a poor filter lap is shown in Figure 13.…”

Numerical simulation of inter‐stage of multistage centrifugal pump by varying number of blades

“…If impellers are mounted on the same shaft, it is used for increasing the head, while the impellers mounted on different shafts cause enhanced discharge capacity. [ 1 ] Having the advantage of producing a higher head and greater discharging capacity, a multistage centrifugal pump can lift extremely viscous fluids such as petroleum products, dirty and sewage‐based water, pulp for paper, sugar molasses, chemical compounds, and so forth. [ 2 ] Because of the longer shaft and higher reliability, multistage centrifugal pumps can have as many stages, rendering them more compliant compared to single‐stage centrifugal pumps for hydraulic design.…”

Performance Enhancement and Numerical Simulation of Inter-Stage of Multistage Centrifugal Pump by varying number of blades Using CFD

“…The basic function of multistage pump is to increase head and discharge. If impellers are mounted on same shaft, it is used for increasing head while the impellers mounted on different shaft cause to enhance discharge capacity [1]. Having advantage of producing higher head and greater discharging capacity, a multistage centrifugal pump is able to lift extremely viscous fluids such as petroleum products, dirty and sewage-based water, pulp for paper, sugar molasses, chemical compounds, etc.…”