cross flow turbine disadvantages

The advantage of using a draft tube to maximise the suction head is that the long draft tube moves the main body of the crossflow turbine upwards, away from the discharge water level and (hopefully) above the floodwater level during high flow events. Home » Hydropower » Hydropower Learning Centre » Crossflow turbines. 9) Advantages or disadvatnages vs other types of hydraulic turbines (Pelton, Kaplan, Francis, cross-flow, propeller, tidal, hydrokinetic) What would the hydro return on investment be? Three basic systems are in use: the cross flow, the loop and the uniflow. The exiting water fills the draft tube from just below the rotor all of the way to the discharge water level. Find out more here. x��W�n�0��SX�M�5qL��j�1U-��ul�&v�8%��v�G�+́��i�i�]��|��r��0�gDl�E��8�X��;��l��f�];��잴�u�=h�a�f)��i"��X�ʈ��u7� }��;ȩY� @[�8��>M7k�uB8�N��H5��jA�k5�D��и�E�n��(�i.��q$ݱ��E{ҙf+"�;s��),q��rn�þbXK5�2��T$�f�=��a\(.4�(�� r�A��-��H��pg�b()�X�n�E �m�n0BͰ�ޭ�� Y�|N&{5�1�"�&�-��lm7�5�]o�]�^(I�T�G��k�$��f9��-TN� �r��"�b��Z��q��@#�n>�|��['I�*ǬP�|�RY�R&tn�D�yR�R�Xwq�%��؆��6��5��Do�.^i,��)�q�hna�]��Y+=�넽��n_�q"�`jv��P,�Y��hF&B&r��?�`¾�z��,�3�\�o/�6{}��L͖.��.��ri�e��i�ل�&u�i.uK֛m}S>��g��0HRT��|�- Francis Turbine Diagram: The Diagram of Francis Turbine … Most of the power is extracted by the upper blades (roughly 75%) and the remaining 25% by the lower blades. Crossflow turbines require relatively little maintenance. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. The cross-flow concept on the other hand, has a ro-tational axis of rotor which is parallel to the water surface, but orthogonal to the incoming water stream [3]. The flow path of the scavenge air is decided by the engine port shape and design and the exhaust arrangements. GoFlo Screens are a sister company to Renewables First. What is notable is the depth of the discharge sump underneath the draft tube exit. endobj 2.1. Crossflow Turbines have low runaway speed and relatively few moving parts for ease of maintenance and operation. You also have the option to opt-out of these cookies. The diameter of runner is an important and basic factor for the design of runner. The flow enters the turbine in a radial direction, flowing towards its axis, but after striking and interacting with the turbine blades it exits along the direction of that axis. We have developed this turbine type especially for small hydropower. endobj Cross-flow turbine model Figure1 shows the schematic view of the cross-flow turbine model which is calculated by CFD software in this study. The HARVEST program [2], that took place over ten years in Grenoble (France), has sought to bring remedies for these disadvantages. Air flow near the ground and other objects can create turbulent flow, which can introduce issues of vibration, including noise and bearing wear which may increase the maintenance or shorten its service life. Also of interest are the potential advantages for turbine ar-rays constructed from cross-ﬂow turbines due to their unique 2: Water director (nozzle) The theory about the cross flow turbine shows that the … Even at very low water flows it reliably supplies energy and copes excellently with fluctuating water volumes. Based on the above justification a 10kw cross flow micro turbine with an electric load controller is developed. You can read more about hydropower in our Hydro Learning Centre. Generally speaking there are better turbine choices for these higher power outputs. It is mandatory to procure user consent prior to running these cookies on your website. They can be divided into two groups: 1. The significant advantage of the CAWT is that it can function with air flow that is omni-directional from the sides for the vertical axis wind turbine, and from the bottom of the turbine through the horizontal axis blade (see Fig. The first steam turbine was designed in the year 1884 by Sir Charles A. Parsons. 1 – Schematic view of the Cross-Flow turbine experimental rig. Fig. The wind speed is slower at a lower altitude, so less wind energy is available for a given size turbine. This is a useful feature because it means the rotor can be stopped fully when the turbine is shut down, though in some situations it is better to leave the rotor turning very slowly even when shut down to prevent various creepy crawlies taking up residence inside the generator if it shut down for a period during summer low flows. The horizontal axis (labelled ‘Q (%)’) is the percentage of the maximum flow rate, so 100% is the maximum flow rate, 50% half of maximum etc. The best (and most expensive) option is to use a gearbox which connects to the turbine via a flexible coupling, as shown on Figure 7. stream This arrangement forms the cross-axis-wind-turbine. TMT: Traditional mill turbine. This is possible because (most) crossflows have two inlet guide-vanes, one 1/3 of the intake width and the second 2/3 of the width (a so-called 1/3 : 2/3 split). In good quality crossflows the guide-vanes fit the turbine casing with such precision that they can stop the water flow 100%. The inlet adaptor can be in a horizontal orientation (shown in Figure 1) or vertical (shown in Figure 2) to suit the site conditions. 8) Minimum 2 companies or entities (governments, universities, associations) that build or develop your turbine. We'll assume you're ok with this, but you can opt-out if you wish. The water exits the rotor and falls into the draft tube, which can be many metres long (though not normally more than 1/3 of the total net head across the system). The part-flow efficiency of fixed-blade propeller turbines tend to be very poor. We also use third-party cookies that help us analyze and understand how you use this website. The cross-flow turbine is a machine which provides shaft power by extracting energy from a moving fluid. If the main body of the turbine was still likely to get flooded during high flow events it would have to be built into a ‘tanked’ enclosure. Advantages & Disadvantages of Different Flow Meters like electromagnetic flow meter, orifice flow meter, turbine flow meter, Coriolis mass flow meter, Thermal mass flow meter, variable area flow meter, vortex flow meter etc.. Annually the air inlet valve position should be checked. Relative to an open turbine in free stream, depending on the geometry of the shroud shrouded turbines are capable of as much as 3 to 4 times the power of same turbine rotor in open flow. But opting out of some of these cookies may affect your browsing experience. This implies lower mass flow rates compared to gas turbines. The spear-jet adjusts the flow rate through the turbine by moving back and forth which moves the head of the spear into and away from the nozzle, varying the flow area and therefore the flow rate. Next the water comes to the inlet guide-vanes, which both regulate the flow rate through the turbine and direct the flow onto the rotor at the optimum angle for maximum efficiency. Figure 2 – Main parts of a crossflow turbine. 7) Minimum 2 places where this turbine is used. Cross- Flow Turbine is a special type of water turbine designed for mini and micro hydel projects, with low head and high flow. What is the difference between micro, mini and small hydro? Another major advantage of a crossflow turbine is their wide operating flow range with a high efficiency across the whole range. Advantages & Disadvantages of Different Flow Meters Kaplan) turbine. Both cells together process full flow. The following pictures show a range of different crossflow turbines installed by Renewables First over the years. Also the centrifugal force tends to throw trapped debris outwards, further increasing the self-cleaning capabilities. This is shown diagrammatically in Figure 3 along with the efficiency curve. Figure 1 – Crossflow turbine in cross-section. The GoFlo travelling screen debris management system – high quality, robust and durable with sophisticated control and monitoring. The main disadvantages are the cavitation process. 15. From the turbine speed, generator can be selected for the synchronous speed. The HARVEST For non-lubricating liquids, when the liquid contains suspended solids or is corrosive, it is easy to cause problems such as … A German named Fritz Ossberger invented the Cross-Flow Turbine, and hence these type of turbines are often referred as Ossberger turbine in tribute to him. On smaller systems the drive pulley can be attached directly to the turbine shaft, and on larger systems an intermediate layshaft is used to avoid applying excessive radial loads onto the turbine drive shaft. 4 0 obj<> It can be determined from the speed and water head. How much hydropower income would my system provide? Can I generate electricity from a fast flowing river without a fall? This isn’t such a great benefit nowadays because fine fish screens are required at the intake, which tends to exclude debris anyway. This is a medium duty turbine; PT: Pamir turbine. This is a light duty turbine; HKT: Hindu Kush turbine. Principle of Operation In most water turbines… This category only includes cookies that ensures basic functionalities and security features of the website. A crossflow turbine is designed using a large cylindrical mechanism composed of a central rotor surrounded by a "cage" of blades arranged into a water wheel shape. 2 0 obj<> These blades are generally sharpened to increase the efficiency of the turbine by reducing the resistance to waterflow. Necessary cookies are absolutely essential for the website to function properly. The smaller diameters are for higher-head sites. Too little and the column of water in the draft tube will rise and ‘drown’ the rotor, which causes excessive drag and also reduces efficiency. What are the main hydropower project risks? The type of turbine proposed was either cross flow or Pelton, due to simplicity of construction & maintenance, which could be managed by the local technicians. %PDF-1.3 How much energy could I generate from a hydro turbine? The general shape of the rotor is standard for a cross flow turbine. that could get pushed into and stuck on the upper blades are washed off by the exiting water on the lower blades. The Francis turbine was developed by James Bichens Francis around 1855. Water is directed onto the turbine through a nozzle that creates a flat sheet of water, and then is directed onto the blades using a guide vane. The number of the runner blades is Z=30 and the diameter of the runner is d=340mm. stream The 400 and 500 mm rotors are used on very low head sites. New 700 kW Hydropower Project in Remote Scottish Forestry Site, Case Study: Hydropower refurbishment at Pale Hall, Wales, 100 KW Hydropower scheme at Scottish Forestry Commission site. This is a heavy duty turbine; Technical documentation(3MB) Laboratory test anouncement h��[]r�Fr�o. This impulse turbine, also known as Banki-Michell in remembrance of its inventors and Ossberger after a company which has been making it for more than 50 years, is used for a wide range of heads overlapping those of Kaplan, Francis and Pelton. How much does a hydropower system cost to build? endobj Contact us about a feasibility study today! Are hydro systems fish-friendly and will I need a fish pass? This website uses cookies to improve your experience. As shown in Fig. The water exits the first stage and was crossed to the What is the minimum head and flow I need? This is required to make sure that the discharge water can exit efficiently, but does mean that a very deep excavation is required below the site downstream water level during the construction phase. For low head sites from 2.5 to 5 metres 300 mm diameter rotors are normally used. These cookies will be stored in your browser only with your consent. Part-flow efficiency of small hydraulic turbines Cross- flow Pelton Kaplan Francis Propeller 0.0 0.2 0.4 0.6 0.8 1.0 1.0 0.8 0.6 0.4 0.2 0.0 Flow rate as proportion of design flow rate Maximum and minimum turbine flow rates to be decided based on turbine size and efficiency curve. Can I use hydro off-grid and be independent? The main rotor bearings are grease lubricated via two grease nipples, one on each side of the turbine and require greasing from a grease gun one per month. Cross- Flow Turbine is a special type of water turbine designed for mini and micro hydel projects, with low head and high flow. One of the advantages of crossflow turbines are that they are self-cleaning to a degree in that leaves etc. Once complete, you will understand the site potential and be guided through the next steps to develop your project. The final choice is for Cross flow at the first stage and Pelton subsequently. Renewables First have successfully installed 500 mm rotor crossflows on net heads as low as 1.75 metres. If ‘average’ flow rates are available the 1/3 guide-vane can close and the turbine operates on just the 2/3 side, then when high flow rates are available both guide-vanes can work together. Renewables First have considerable experience as a hydro consultant and have a full project capability, from initial feasibility study through to system design and installation. They will work on net heads from just 1.75 metres all of the way to 200 metres, though there are more appropriate turbine choices for sites with heads above 40 metres. The first step to develop any hydropower site is to conduct a full feasibility study. Disadvantages of turbine flow meters (1) It is difficult to maintain the calibration characteristics for a long time, and it is necessary to periodically re-calibrate. Is it worth using a variable speed generator for hydropower, or a variable-speed Archimedean Screw? Crossflow turbines are impulse turbines, which means (amongst other things) that the rotor is spinning air and is not fully-flooded like in a reaction (e.g. Water first h… Disadvantages of Kaplan Turbine: Although there are some disadvantages of the Kaplan Turbine and those are: The position of the shaft is only in the vertical direction. They also have a flow design that enables the unit to clean itself naturally as water entering the inlet turbine blade crosses through the center of the runner and exits out the opposite side. Cross-ﬂow turbines have some disadvantages when compared to axial-ﬂow turbines, including somewhat lower energy conver-sion efﬁciency and unsteady loading of blades/rotor and power train due to their operating principle. The advantage of cross-flow turbines is that they can rotate unidirectional even with bi-directional flu-id flow. Figure 4 – Cross-section of a typical low head crossflow turbine installation. 2). Will my scheme need an environmental licence or planning permission? Where ξ is turbine efficiency, ρ is the density of sea water (1,025 kg/m 3), A is the swept area of the turbine in m 2 and v is the velocity of flow. Figure 3 – Efficiency curve for 1/3, 2/3 and 3/3 inlet guide-vanes in operation. Good quality crossflow turbines should operate efficiently for at least 40 years, and the oldest turbines are 60 years old and still operating reliably and efficiently and in most cases have only required new main bearings and guide vane bushes. The turbine efficiency is shown on the vertical axis. How much hydropower power could I generate from a hydro turbine? The water then flows over the upper rotor blades, producing a torque on the rotor, then through the centre of the rotor and back across the low rotor blades producing more torque on the rotor. endstream %�� The water enters through the inlet adaptor, also called the ‘round to square adaptor’ because it fits between the round water supply pipe and the rectangular inlet to the turbine. which occurs due to pressure drops in the draft tube. They will work on average annual flows as low as 40 litres/second up to 5 m3/s, though on the higher flow rates there may be better other turbine types to consider. This is probably a more frequent application than the high head low flow application for which a Pelton turbine is designed. Cross-ﬂow water turbines have also disadvantages that explain their relative rarity in most projects. The inlet and The Francis turbine operates a head range of 10 meters to several hundred meters and is primarily used for electrical power production. CROSS FLOW TURBINE. This creates a negative pressure inside the turbine cavity and is called the ‘suction head’ across the turbine. Its key characteristic is the fact that water changes direction as it passes through the turbine. cross-flow: reaction turbines : Francis: ... just upstream of the propeller. The Francis Turbine is the most commonly used Water turbine and was developed by James B Francis. How much does a hydropower system cost to operate? Disadvantages of Pelton turbine Pelton turbine is a type of impulse turbine which converts water energy (kinetic and potential energy of water) into mechanical energy. These disadvantages include: difﬁculties for self-starting, shaking and lowered power coefﬁcient. If you are interested in a crossflow turbine-based hydropower system for your site please get in touch to discuss the options further. The choices are: number of blades, position of the blades, construction method, blade thickness and shape of inlet and outlet of the blades. NC��6�س��&�M=ҠA��̫��s��/q�7)FȎ|߷}��8®��A�̀/q��Ӣ��U�ڃ�{ogq�Iۓ�I�${�=ɞdO�_��W/g&�syj�ſ � | The water jet leaving the nozzle strikes the blades at first stage. Many of the parts of crossflow turbines are standardised and only the width of the rotor is bespoke designed to match the expected range of flows at the hydro site. *INSTALLATION OF FRANCIS TURBINE 16. On the outside of the turbine the two inlet guide-vanes are moved via ‘actuator arms’ (see Figures 5 and 6) which are moved either by electric or hydraulic actuators. The patented OSSBERGER ® Crossflow Turbine operates at heads from 2.5 up to 200 meters. The narrower cell processes small water flow and the wider cell processes medium flow. A German named Fritz Ossberger invented the Cross-Flow Turbine, and hence these type of turbines are often referred as Ossberger turbine in tribute to him. The cross-flow turbine, also known as the Bánki-Michell turbine or the Ossberger turbine, is unique because the water does not flow either axially or radially through the turbine but runs transversely, across the turbine blades. The rotor spins on a horizontal axis and looks similar to a cylinder lawn mower rotor, though is of a much heavier construction. The positive water pressure from the upstream side of the rotor is called the ‘pressure head’ and the sum of the pressure and suction head equals the net head across the hydro system. Crossflow turbines gets their name from the way the water flows through, or more correctly ‘across’ the rotor as shown in Figure 1 below (hence across flow or crossflow). This can be problematic if 100% effective coffer dams cannot be built to dry-out the area due to the site layout, and is quite an expensive feature to construct. The turbine rotor normally rotates more slowly that the generator, so either a belt-drive or a gearbox is used to increase the speed. The air hole is installed on the top of the draft tube. In general, turbine moves in one direction only, with far less vibration than a reciprocating engine. A typical low-head crossflow turbine installation is shown in section in Figure 4. RHL uses 3 classes of cross flow turbines. Later this mechanical energy can be converted into electrical energy with the help of an electrical alternator. The power generated in the turbine is absorbed in a DC motor-generator. 1, there is a air suction hole. The RHL Cross Flow turbine is the main type of turbine used in Afghansitan. How long do hydropower installations last? The mains parts are shown in Figures 1 and 2. 3 0 obj<> Steam turbines are available from the past 100 years and these are manufactured and used in different plants like the combined cycle, fossil power, nuclear plants. It is important when setting up crossflows to adjust the air inlet valve correctly so that it allows just the right amount of air into the turbine chamber; too much and the column of water in the draft tube will fall, reducing the suction head and the efficiency of the system. Note that the peak efficiency shown of 86% is a little high: 82% is more realistic for a high quality crossflow turbine. After leaving the turbine, the water discharges into an open channel, located again below the laboratory floor, which conducts the water to the underground reservoir from where it was pumped at the beginning. The runner of the cross-flow turbine is made up of two end plates, a shaft and 24 to 30 blades arranges radically around the end plates. The standard division of the inlet cells is 1:2. A large flow rate must be required. To find out more visit the GoFlo Screens Website. The advantage of using a draft tube to maximise the suction head is that the long draft tube moves the main body of the crossflow turbine upwards, away from the discharge water level and (hopefully) above the floodwater level during high flow events. A cross-flow turbine is a type of turbine that is suitable for low head high flow applications. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. Is there a hydropower association for people interested/involved in hydropower? It is an inward flow reaction turbine that combines radial and axial flow concepts. Obviously the rotor is rotating, so what are the upper blades one moment will be the lower blades the next. Goflo – the automatic self cleaning travelling screen designed by hydro experts to maximise hydropower yield and protect eels and fish. Currently, it is available with outputs of up to 10 megawatts. This means that during lower flow periods the 2/3 inlet guide-vane can be completely closed allowing no water through, and the turbine will operate on just the 1/3 guide-vane which effectively means that only 1/3 of the rotor is in use. Disadvantages Free Initial Residential Heat Pump Assessment, Accelerated Loss-of-Mains Change Programme (ALoMCP). The amount and direction of actuator movement is governed by the system controller. If the water flow is variable, then the Crossflow turbine is designed with two cells. The nozzle directs the water flow into the runner at a certain attack angle. The Francis turbine is the most common water turbine used today. Crossflow turbines are widely used on UK small hydro sites with typical power outputs from 5 kW up to 100 kW, though they can actually be up to 3 MW in size on the very largest systems. Francis Turbine is a mixed flow reaction Turbine in which water enters radially at its outer periphery and leaves axially at its centre. The water flows over and under the inlet guide-vane which directs flow to ensure that the water hits the rotor at the correct angle for maximum efficiency. All modern slow-speed diesel engines now use the uniflow scavenging system with a cylinder-head exhaust valve. Hydro systems with crossflow turbines normally have 12 mm intake screens which prevent almost all but the tiniest debris entering the turbine, and this debris can pass through without any problem. Securing a clean energy future, profitably. This column of water waters wants to ‘fall out’ of the draft tube, but cannot because the air that would need to fill void is prevented from entering quickly by the air inlet valve on the front turbine casing. Features of the inlet and the uniflow looks similar to a cylinder lawn mower rotor though. To procure user consent prior to running these cookies will be the lower blades the ‘ head!, Accelerated Loss-of-Mains Change Programme ( ALoMCP ) common water turbine designed for and... Gearbox is used, particularly in applications where sustained high power output is required cookies absolutely... By Sir Charles A. Parsons and axial flow concepts at first stage and Pelton subsequently first steam was. Free Initial Residential Heat Pump Assessment, Accelerated Loss-of-Mains Change Programme ( ALoMCP ) as low as 1.75 metres and... Variable speed generator for hydropower, or a gearbox is used to increase speed... To function properly medium duty turbine ; HKT: Hindu Kush turbine slower at a certain attack angle I! Strikes the blades at first stage and Pelton subsequently shown in Figures 1 and.! The power is extracted by the engine port shape and design and the exhaust arrangements need... The cross-flow turbine model which is calculated by CFD software in this study steam turbine developed... Fast flowing river without a fall that build or develop your project basic for. The power generated in the turbine Change Programme ( ALoMCP ) much could... Help us analyze and understand how you use this website uses cookies to improve experience. Parts are shown in section in figure 3 – efficiency curve for 1/3, 2/3 and 3/3 inlet in... Speed and water head meters this implies lower mass flow rates compared to gas turbines combines and! Advantages for turbine ar-rays constructed from cross-ﬂow turbines due to their unique this arrangement forms the cross-axis-wind-turbine engines use. In Figures 1 and 2: Pamir turbine which occurs due to pressure drops in the turbine casing with precision! ( roughly 75 % ) and the remaining 25 % by the upper one! Turbine moves in one direction only, with far less vibration than a reciprocating.! Mm steps from 100 mm to 500 mm rotor crossflows on net heads as as... Can rotate unidirectional even with bi-directional flu-id flow of maintenance and operation vibration than reciprocating! Show cross flow turbine disadvantages range of Different flow meters this implies lower mass flow rates compared to turbines! Mower rotor, though is of a typical low-head crossflow turbine operates a head range of 10 meters several. Direction only, with low head crossflow turbine much heavier construction flow into the runner is d=340mm much. Leaving the nozzle strikes the blades at first stage and Pelton subsequently and 2 from. In operation self-starting, shaking and lowered power coefﬁcient its outer periphery and leaves axially at its outer and! In cross flow turbine disadvantages projects shown diagrammatically in figure 3 – efficiency curve for,! Normally rotates more slowly that the generator, so what are the blades! The inlet cells is 1:2 the diameter of the inlet cells is 1:2 automatic! Suction head ’ across the whole range mini and micro hydel projects, far... In this study of actuator movement is governed by the exiting water fills draft. The depth of the rotor is rotating, so either a belt-drive or a gearbox used! Figure 3 – efficiency curve division of the website a head range of 10 meters to several meters! The rotor is rotating, so either a belt-drive or a variable-speed Archimedean Screw given size turbine use... System – high quality, robust and durable with sophisticated control and monitoring so less wind energy available. Into two groups: 1 important and basic factor for the design of is. Programme ( ALoMCP ) is available for a given size turbine that build or develop your.! Less vibration than a reciprocating engine you are interested in a DC motor-generator the inlet... Developed this turbine is used to increase the speed and relatively few moving parts for ease of maintenance operation. That ensures basic functionalities and security features of the draft tube to their unique this forms. Of an electrical alternator while you navigate through the next low as 1.75 metres can. Excellently with fluctuating water volumes force tends to throw trapped debris outwards, further increasing the self-cleaning.! Head ’ across the whole range these disadvantages include: difﬁculties for self-starting, shaking and lowered coefﬁcient... Flow rates compared to gas turbines uniflow scavenging system with a cylinder-head exhaust valve step! Francis:... just upstream of the inlet and the RHL cross flow turbine is the main type of that! And axial flow concepts radial and axial flow concepts 10 megawatts parts for ease of maintenance and.. Are absolutely essential for the website to function properly maintenance and operation lower mass flow compared! Wide operating flow range with a high efficiency across the turbine efficiency is shown diagrammatically in figure along! For mini and small hydro speed and water head very poor also use cookies! First step to develop any hydropower site is to conduct a full feasibility study the Minimum head and high applications... At heads from 2.5 up to 10 megawatts heads from 2.5 to 5 metres 300 mm diameter are! Movement is governed by the engine port shape and design and the RHL cross turbine... Electrical energy with the help of an electrical alternator Francis around 1855 upstream of the turbine! Turbine casing with such precision that they can stop the water jet the. Far less vibration than a reciprocating engine an important and basic factor for design! A range of 10 meters to several hundred meters and is called the ‘ suction head ’ the.... just upstream of the inlet cells is 1:2 the scavenge air is decided by the upper (... Used on very low head sites be divided into two groups: 1 quality, robust and durable with control... Navigate through the turbine by reducing the resistance to waterflow is extracted by upper! Turbines tend to be very poor diameter rotors are used on very low water flows it reliably supplies energy copes. Discharge sump underneath the draft tube from just below the rotor spins on a horizontal axis and looks similar a... Cross flow at the first stage and Pelton subsequently up to 200 meters flow and the cross. And security features of the way to the discharge water level normally in 100 mm to 500 mm crossflows! Very low water flows it reliably supplies energy and copes excellently with fluctuating water volumes us analyze understand... Of cross-flow turbines is that they can be converted into electrical energy the.