Hydro Turbines and Small Hydro Power Plants: BreFix Technologies
We rank among the leaders in deliveries of technology for small and medium-sized hydropower stations. The goal of the development team of Our Partnering Manufacturers is to change water potentials together with our customers all over the world into profitable and environmentally-friendly sources of energy.
We are one of the few companies in the world using the know-how that is necessary for the realization of technically perfect deliveries of all important types of turbines, such as the Crossflow, Kaplan, Pelton and Francis turbines, up to a capacity of 5 MW per unit. Besides that, Our Partnering Manufacturers specializes in the installation of hydropower stations in drinking water systems and holds several licences for that purpose.
Each of our Hydro Turbines is tailor-made for a specific purpose and guarantees:
- High efficiency
- Extremely long service life
- High operational safety
- Minimum maintenance requirements
- Low operating costs
Perfect customer care prior to and following the purchase, multilingual team and ISO 9001:2001 + ISO 14001:2004 certification, all this supports our positive-minded company profile.
2-cell Crossflow Turbine
Our Crossflow turbines are designed correspondent to the Ossberger type. They are made of standardized components configured according to customer requirements – i.e. the quantity of water and the head of the particular location. Such a modular system enables short delivery times and good prices at the same time.
Crossflow turbines have a long service life and they are almost maintenancefree. During operation, they do not require any costly or complex spare parts; repairing them is feasible on site. A specific advantage of Crossflow turbines is the possibility of using them in drinking water systems, even in very long conduits, not causing undesirable water hammer effects and thus not affecting the quality of drinking water during operation. This has been successfully tested by our company several times in numerous countries around the world.
Operating turbine range
- Head height: H = 3… 200 m
- Flow: Q = 0,03… 13 m³/s
- Capacity: N = 10… 3 500 kW
Principle of a 2-cell Crossflow Turbine
Crossflow turbines are radial, slightly overpressure turbines with tangential injection of the runner blades and with a horizontal shaft. They rank among low-speed turbines. The water flow comes through an inlet pipe, then, it is regulated by guide vanes and finally enters the runner of the turbine. After passing through, the water leaves on the opposite side of the runner, providing so additional efficiency. Finally, it flows from the casing either freely or through a draft tube to a stilling basin under the turbine.
| fig.1: Horizontal inlet | fig.2: Vertical inlet |
If the water flow is variable, then the Crossflow turbine is designed with two cells. The standard division of the inlet cells is 1:2. The narrower cell processes small water flow and the wider cell processes medium flow. Both cells together process full flow. As a result, the water flow is used from 100 to 12 % with maximum efficiency, and the turbine is able to start operation even with only 6% of the design flow.
In practice, the water flow in the runner provides a self-cleaning effect. Any impurities that are pushed between the blades when water enters the runner are also pulled out by centrifugal force.After a half revolution of the runner, the water takes the impurities out of the runner and flushes them away to the stilling basin.
Level of turbine efficiency
The total efficiency of small Crossflow turbines with a small head is between 80-84% throughout the flow. The maximum efficiency of medium and big turbines with a higher head is 87%.
The advantages of a partially loaded Crossflow turbine are illustrated by the efficiency curve shown in fig.3. The actual river flows are very small for several months of the year, if compared to the design flow of the turbine. During those months, the energy production depends solely on the ability of the turbine to utilize these partial flows efficiently. As a result, our two-cell Crossflow turbines with their flat curve of efficiency achieve higher annual energy output, than turbines reaching high efficiency with full flow, but rather low efficiency with partial flow.
fig.3: Crossflow turbine curve of efficiency, if the flow is regulated by guide vanes in the proportion of 1:2, compared to a Francis turbine.
Turbine casing
The casing of a Crossflow turbine is made of structural steel; it is robust, resistant to impacts and frost. If there is high contents of abrasive material in the water (e.g. sand, silt) or if the the actual composition of the water is considered aggressive (e.g. sea water, acidy water), all parts of the turbine in contact with water are made of stainless steel.
Guide vanes
In a split Crossflow turbine, the working water is directed by two force-balanced profile guide vanes. The vanes split the water beam, balance it and let it enter the runner smoothly – independently of the width of the cells. Both rotary guide
vanes are set precisely in the turbine casing and they can serve as the closing device of the turbine if there is a lower head. Then it is not necessary to use a shutoff valve between the pressure piping and the turbine. Both guide vanes are fitted independently with extended arms, to which automatic or manual control is connected. Guide vanes are placed in highly resistant slide bearings, which do not require any maintenance. The turbine will be able to close by gravitation in the event of its shutdown, by added weights to the arms ends.
fig.4: Design of a two-cell Crossflow turbine
Runner
The runner is the most important part of the turbine. It is equipped with blades which are made of polished drawn profile steel by a well-proven method. Depending on the actual hydraulic data, either structural steel or stainless steel is used for their construction. Both ends of the blades are fitted in runner discs and welded with intermediate discs of the runner following a specific procedure. Depending on the size, the runner has up to 37 blades. The linearly slanted blades create only slight axial force and therefore reinforced axial bearings with complex fitting and lubrication are not required. Blades of wider runners are supported by multiple discs. Runners are carefully balanced before final installation of the turbine and are subject to crack detection control.
Bearings
Crossflow turbines are equipped with self-aligning roller bearings having several advantages, such as low rolling resistance and simple maintenance. The design of the bearing housing prevents water leakage into bearings and contact of lubricants with working water. This is an important quality of the patent design of our Crossflow turbine bearing housing. Furthermore, the runner is centred in the turbine casing by means of the bearings. Such an inventive technical solution is completed with maintenance-free sealing elements. Apart from grease change every year, the bearings do not require any maintenance. Moreover, the used technical solution enables simple replacement of the runner without taking the entire turbine out of its position.
Draft Tube
The Crossflow turbine is a free stream turbine, just like a Pelton turbine. However, in case of medium or low head, it is possible to apply a draft tube in order to utilize the entire head. The water column in the draft tube must be controllable, though. This is ensured by a regulation air valve, affecting the suction pressure in the turbine casing. In such a manner, turbines with a suction head from 1 to 3 m can be optimally used without any danger of cavitation.
Application
- 10 kW-3.500 kW/unit
- Head range: 5-200 m
- Run of river SHPP
- Dam SHPP
- SHPP in drinking water systems
- SHPP in wastewater treatment plants
- SHPP for electrification of remote areas
Advantages
- Increased annual production because of high efficiency
- from 12% to 100% of flow
- Starts operation with only 6% of flow
- Tailor-made for every installation
- Non-clogging runner
- Highly tolerant against varying head
- Simple installation and minimal civil works
- Almost maintainance-free
- Highly tolerant against foreign substances
- Proven quality from almost 10.000 installations
Control systems for SHPP
Safe connection to the power grid with optimum efficiency of the turbine.
Our Partnering Manufacturers offers you high quality control systems and switchboards for:
- Grid parallel operation focused on achieving the maximum annual production
- Autonomous (isolated) operation, for internal consumption of the customer, with excess energy dissipation
- Combination of grid parallel operation and autonomous operation with the option of a “blackstart”
PLC SIMATIC touch screen panel ensures 100% capacity and functional control of your turbine on site or via Internet.
- Option of remote control, monitoring and diagnostics
- Fully automated power plant operation
- Use of the best-quality components
- En-block construction enabling easy diagnostics
Small hydro powerplants
Our Partnering Manufacturers is your partner in designing and constructing complete hydropower stations
„There is water at the beginning and there is a connection to the electricity supply network at the end“
Our delivery will include:
- A trash-rack cleaning machine, including accessories
- Closing valves of the inlet and by-pass
- Turbines
- Piping and steel structures
- Gearboxes / belt drives / clutches
- Asynchronous or synchronous generators
- Control systems of turbine sets
- Generator control panels
- Hydraulic systems
- Planning and design
- Assembly
The optimal adjustment of included components, as well as their high efficiency, will ensure fast return of your investment.
Power stations in drinking water systems
Our Partnering Manufacturers are specialized in deliveries of turbine sets for drinking and wastewater systems. This is possible due to the structure of the used Crossflow and Francis turbines, which are designed hydraulically in such a manner that the smallest possible hydraulic impacts are achieved even with big lengths of pipes. Crossflow turbines may be used in wastewater systems thanks to the self-cleaning capacity of the runner.
The used system of the turbine control and the turbine bearing system guarantee that the hygienic quality of working water and its permanent classification as drinking water are maintained at 100%. Waterworks and sewage disposal plants are facilities with high power consumption. The installation of a small hydropower station will change them into energetically self-sufficient units and will in many cases even enable sale of excess energy to the public electricity network. During installation of a small hydropower station in drinking water systems, it is not necessary to stop the water supply to residents for a long time, and it will not get polluted.
We utilise our experience in numerous installations in the Czech Republic, Slovakia, Italy, Finland, Romania, Bulgaria and other countries around the world.
Trash-rack cleaning machines
Trash-rack cleaning machines reliably remove deposited foreign bodies from the protective rack in front of the inlet openings and ensure unobstructed flow of water to the turbines.
Depending on the scope of contamination, trash-rack cleaning machines secure high energy use of your hydropower station. In particular, in the autumn when leaves fall from the trees or in the winter when ice covers some parts, cleaning machines can guarantee an increase in capacity of up to 30%.
Our Partnering Manufacturers offers specific cleaning machines for any type of trash-racks, depending on the design:
- Telescopic cleaning machines for screens up to 3.5m width and 1.5m height
- Stationary hydraulically controlled cleaning machines for screens up to 8m width and 10m height
A common feature of all design types is high quality, guaranteeing trouble-free operation for several decades:
- Robust, steel construction, resistant to distortion
- Completely hot galvanized
- Maintenance-free bearings with permanent lubrication
- Oil hydraulic equipment with pressure limit switches
- This type of cleaning rake does not require any alignment of racks
- The cleaning rake is made of a material which is highly resistant to wear
- The cleaning algorithm is controlled automatically by means of water level sensors or switch relays
- We also offer frost-resistant heated belt conveyors
Services & Technical Support
Our Partnering Manufacturers provides
- supervision of turbine installations
- inspection of installed equipment
- commissioning of power plants
- instruction of power plant personnel
- maintenance of equipment delivered by Our Partnering Manufacturers according to customer’s requirements
- old hydro power plant refurbishment
- remote monitoring of power plant features over the Internet
- online technical assistance, flexible solutions, fast response time
- software updates