Recently, Liancheng Group has successfully completed a project to improve the efficiency of submersible sewage pump units. The improvement project relied on the "WQ new generation of high-efficiency submersible sewage pump" technology development route in the group's municipal high-tech transformation project to overcome difficulties and finally succeeded. The project results were successfully applied to the sewage pump station renovation project.
1. Results
The project ensures the maximum particle passing capacity, and focuses on the basic research of external characteristics and internal flow characteristics to improve the unit efficiency around the multi-scheme hydraulic simulation technology. After testing the hydraulic performance of the real machine, the efficiency values of the prototype and the prototype after cutting are significantly higher than the first-level energy efficiency value of the sewage and sewage submersible electric pump unit. The data is shown in Table 1.
Table 1 Submersible sewage pump unit efficiency and first-level energy efficiency value
| Submersible sewage pump type | Actually measured unit efficiency | Sewage and sewage submersible electric pump unit efficiency first-level energy efficiency value |
| 300WQ700-
14-37 |
76.10% | 64.80% |
| 300WQ700-
11-30 |
75% | 64.50% |
Through the actual measured data and data comparison of the submersible sewage pump, it was found that:
(1) The actual hydraulic performance test results showed that the unit efficiency exceeded the first-level energy efficiency value of the sewage and sewage submersible electric pump unit efficiency.
(2) The actual hydraulic performance test results showed that the high-efficiency area of the electric pump completely covered the pump flow operating range of 0.7~1.3Qd specified in the national standard GB/T 24674-2021 for sewage and sewage submersible electric pumps, achieving the effect of high efficiency and wide performance.
(3) The actual hydraulic performance test results showed that when the impeller outer diameter cutting amount reached 8%, the unit efficiency only decreased by 1.1%.
2. Project Achievements
The number of impeller blades and the blade outlet width are the core parameters of the wide flow channel non-clogging impeller design. The project research fully considered the maximum diameter value of the passing particles and the unit efficiency.
Usually, when the number of blades decreases, the blade's ability to constrain the liquid flow becomes worse, axial vortices are formed in the flow channel, the internal flow state is turbulent, and the liquid flow loss along the way is increased. The impeller of this improvement project adopts a wide outlet, which intensifies the secondary recirculation phenomenon formed at the blade outlet edge. Both factors restrict the improvement of unit efficiency. The actual machine test data shows and compares that the project has achieved success at a specific speed of 220-260.
3. R&D process
The project results are inseparable from the key hydraulic R&D technologies accumulated by Liancheng's technical team and the correct submersible sewage pump design technology route.
(1) The design is based on the same pump body. Under the geometric shape of a small number of blades, the blade outlet width, blade outlet placement angle, and impeller outer diameter are combined to find the best solution in multiple dimensions.
(2) The design comprehensively considers multiple factors such as blade wrap angle, impeller outer diameter, blade outlet width, impeller inlet diameter, and blade inlet position to ensure the particle passing capacity.
(3) The blade inlet edge is uniquely treated in the design to effectively prevent fiber entanglement.
(4) The design of a wide flow channel pump body with a large base circle width section design is matched with a wide flow channel non-clogging impeller to ensure that particles can be discharged smoothly through the impeller along the pump body.
4. Transformation of achievements
The group company has complete sewage pump technology development capabilities and perfect production and manufacturing inspection capabilities. The submersible motor, sewage pump, and electric control cabinet have more than 30 years of design, production and manufacturing industry experience in the group, providing a complete solution for the upgrading and transformation of sewage pump station pump equipment
Post time: Feb-08-2025