On optimization of flow passages of impellers of centrifugal pumps

The conventional solution for HAPPs is the use of reversible hydraulic machines operating both in the pump mode as well as in the turbine mode. At the same time, for example, a blade system of a hydraulic machine designed for the pumping mode has a high efficiency. However, in the turbine mode, the energy characteristics of such machine are far from optimal. Considering different patterns of micro- and mini-HAPPs (up to 100 kW) of modular design, it is most appropriate to use a pump and a turbine separately, since the efficiency of hydraulic machines is very important in the case of such low power. To date, approaches to the design of hydraulic turbines are quite developed and allow to achieve high energy performance [1, 2]. According to different data sources the level of axial turbine efficiency with power less than 100 kW is about 80÷91%. At the same time, for centrifugal pumps, especially those of low specific speed, the problem of increasing energy efficiency is very urgent. E.g., for pumps with a specific speed ns< 80 the efficiency level is usually 40 to 65%. The aim of the presented research is the development of methods of synthesis and optimization of the flow passages of centrifugal pumps using the approaches of the theory of optimal control and increasing energy performance of hydraulic machines. Various ways of local correction of geometry of flow passages are presented in the paper. As an alternative to empirical approaches, methods based on the control of the circulation distribution are considered in detail. Various mathematical dependences of the flow circulation on the coordinate of the point lying on the surface of the blade are analyzed. Possibilities of application of the theory of experiment planning in relation to the problems to be solved are considered.

1. Kaczmarczyk T. Z., Żywica G., Ihnatowicz E. The impact of changes in the geometry of a radial microturbine stage on the efficiency of the micro CHP plant based on ORC. Energy 2017; (137): 530–543. (In Eng.)

2. Parygin A. G., Volkov A. V., Ryzhenkov A. V., Naumov A. V. and Druzhin A. A. Optimi-zation Algorithm of Parameters of Low Head Microhydropower Plant at an Early Design Stage. International Journal of Applied Engineering Research 2016; 22(11): 10878–10886. (in Russ.)

3. Caborca P. C., Lomakin V. O., Kuleshova M. S., Baulin M. N. Optimisation of the flow part of the pump is sealed by a method of LPTau search. Pumps. Turbines. Systems 2016; (1): 55–61. (In Eng.)

4. Troshin G. A., Petrov A. I. Methods of modification of the flow part of NM type oil pumps 2014; (11): 87–92. (in Russ.)

5. Checcucci M., Schneider A., Marconcini M., Rubechini F., Arnone A., De Franco L., Coneri M. A novel approach to parametric design of centrifugal pumps for a wide range of specific speeds. In Proceedings of the 12th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows 2015. (In Eng.)

6. Gergel V., Grishagin V., Gergel A. Adaptive nested optimization scheme for multidimensional global search. Journal of Global Optimization 2016; 66(1): 35–51. (In Eng.)

7. Zakharova E. M., Minashina I. K. Review of multidimensional optimization methods. Information processes 2014; 3(14): 256–274. (in Russ.)

8. Glad T. and Ljung L. Control theory. CRC press 2014. (In Eng.)

9. Volkov A. V., Parygin A. G., Naumov A. V., Vikhlyantsev A. A., Druzhinin A. A., Grigoriev S. V. Application of optimal control theory methods for the development of highly efficient centrifugal pumps. International Journal of Applied Engineering Research 2017; 19(12): 8768–8778. (in Russ.)

10. Sidnyaev N. I. theory of experiment planning and analysis of statistical data 2018. (in Russ.)

11. Locallow G. A., Markovskiy V. M. Axial and centrifugal pumps of thermal power plants. 2016. (in Russ.)

12. Turk V. I. Pumps and pumping stations 2014. (in Russ.)