Projects / Programmes
Optimization of operation of water turbines with horizontal shaft and low submergence
| Code |
Science |
Field |
Subfield |
| 2.03.04 |
Engineering sciences and technologies |
Energy engineering |
Energy systems |
| Code |
Science |
Field |
| T140 |
Technological sciences |
Energy research |
| Code |
Science |
Field |
| 2.03 |
Engineering and Technology |
Mechanical engineering |
Water turbine, low submergence, cavitation
Researchers (12)
Organisations (2)
Abstract
According to EURELECTRIC the EU will need 750 GW of new electricity generating capacity to meet increasing demand and to replace aging plants. Electricity production by hydropower plays a significant role in the EU through covering over a tenth of the European production with roughly one fifth of the installed capacity.
Largest remaining hydro potential in Europe lies in low head < 15m plants (SETIS). According to SETIS there is a need for an increased and more focused R&D geared to harness the untapped hydro-potential in Europe while ensuring a high degree of sustainability and compliance with the Water Framework directive.
However, very low head hydro power plants exhibit unsteady characteristics due to variation of static pressure load to the blades. Among them the most important is cavitation, which causes drop in efficiency, vibration, noise and erosion. To avoid the mentioned problems the minimal submergence of the impeller is given by standard (IEC 60193). This approach is not suitable for turbines with horizontal shaft and low river head. Consequently asymmetric pressure field develops at turbine intake. The blades travel from lower to higher pressure region and back. Determination of optimal operating point of a turbine with horizontal shaft significantly contributes to more efficient use of energy sources. Low head turbines with horizontal shaft enable harvesting energy from rivers with low drop. Additionally no dam needs to be constructed what significantly decreases the impact on the environment and reduces construction costs, which contribute about 2/3 of the whole investment.
We intend to design a turbine, which will operate closer to the cavitation condition with minimal negative effects. We will study asymmetrically designed guide vanes, which will enable optimal distribution of pressure and at the runner intake and consequently reduce negative cavitation effects. The influence of the varying static pressure at turbine rotation will be investigated on a profile in cavitation tunnel where the system pressure will be changed periodically. This way the influence of varying pressure on the dynamics of cavitation and on the aggressiveness of cavitation erosion will be determined.
Numerical methods will include modeling with commercial and open code programs which we will improve by considering the time dependent boundary conditions (influence of variable static pressure), improved description of turbulence, consideration of compressibility of the 2 phase flow and fluid-structure interaction.
By simultaneous measurements of pressure, efficiency, vibration, noise and visualization of cavitation on a turbine model we will improve the know how from the previous experiments. We will use improved numerical methods to simulate the flow through the turbine, accurately predict cavitation and optimize the shape of the parts of the turbine flow tract.
In the final phase of work package we will design and test a prototype turbine with asymmetrical guide vanes that will enable optimal pressure field in the impeller and enable lower impeller submergence. For quick dissemination of the results we intend to present the work at least 5 scientific and professional conferences. Additionally we will publish it in at last 10 reviewed journal papers. We will support graduate and postgraduate studies and put effort into educating of employees in industry. The final goal of dissemination is the introduction of a new methods for determination of minimal submergence of turbines with horizontal shaft. Experimental and numerical part of the basic research and numerical part of the applied research will be executed in the LWTM. The experimental part of the applied research will be performed at LitostrojPower. Laboratories are equipped with all the necessary tools for project execution. Experiments for additional evaluation of results could be done at TU-Muenchen (Germany), Arts et Métiers ParisTech (France) and ČKD Blansko (Czech Re
Significance for science
In today's rapidly changing and developing world we should at the society level look for the sustainable protection of the environment. Among this, a sufficient amount of clean energy is required. Hydropower is among the most important clean energy resources, but most of the water resources in the developed world are already exploited, with the notable exception of most rivers with low available head. Rivers with low head in Slovenia and Europe are still not exploited for energy production due to high costs of power plant erection. High efficiency of these power plants at a reduced need for submersion depth allows the use of alternative water sources, the same is true for power plants that operate on the principle of sea tide . The project developed methodology for the design of water turbines that will operate with a low head and low submersion depth. With modern experimental and numerical methods, we have shown that it is possible to improve the design of water turbines operating at low head and low submersion depths. For this, we performed numerical and experimental studies of cavitation. Cavitation is one of the few pending scientific areas, wherein, in particular relative to other engineering disciplines is poorly understood area of cavitation erosion. In the area of cavitation erosion, we have published several high-profile scientific papers.
Significance for the country
Development of water turbines is one of the oldest areas of engineering. In Slovenia, which is with hydropower rich country, are large water turbines already in operation for about 100 years. Knowledge of the development and manufacture of large water turbines has a strong presence in Slovenia. With the development of turbines and their production in Slovenia in a large number of companies is engaged, among them a large company Litostroj Power d.d. is present in more than 50 countries around the world and has manufactured and supplied to customers more than 450 turbines with more than 17 GW of electric power. With a successful appearance on the global world market in addition to the economic benefits slovenija benefits on visibility of identity. Most countries , among them are included technologically developed countries, does not have a production capacity for large water turbines. In this context, Slovenia abreast of the few countries that have ability of large water turbines manufacture, such as the U.S. , Japan , Germany , Austria , France , Russia and China. Our mission is to preserve both the recognition and identity of Slovenia, to which contributed also the results of this project . For successful performance on the market, the manufacturer of large water turbines must cope with global competition. This is only possible with excellent knowledge and good organization of the company. On excellent knowledge and good organization depends a large number of jobs in manufacturing, service, and other related activities, associated with the production program of water turbines. At the same time it is a field of engineering, where the vast amount of knowledge is embedded in the product and therefore added value of the product is very high. The knowledge that we have obtained within the project is available to the user Litostroj Power d.d. , while at the volju the Faculty of Mechanical Engineering . For Litostroj Power d.d. project results in more favorable position in the global world market. At the same time for the project modern numerical and measurement methods were used at the Faculty of Mechanical Engineering. These can be used again or upgraded for future projects in the field of development of large water turbines or for the development of related technical areas of turbomachinery, for which in Slovenia, a large number of manufacturing companies exist.
Most important scientific results
Annual report
2010,
2011,
2012,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2010,
2011,
2012,
final report,
complete report on dLib.si
