ES2361100A1 - Watertiger multiplier with controlled atmosphere. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

The present invention relates to a wind turbine gearbox with a power supply (t, z, o), which introduces an inert gas at a pressure higher than atmospheric inside the tank to prevent the entry of air and prevent oxidation of the oil, and which has control means connected to a set of sensors (u, x, n) to manage the opening and closing of some regulation valves and a set of controlled opening vents (l). (Machine-translation by Google Translate, not legally binding)

Description

Wind turbine multiplier with atmosphere controlled.

Summary of the invention 1. Scope of the invention

The present invention relates to the scope of wind turbines and, specifically, oil systems, and be of hydraulic oils or lubrication.

2. Fundamentals

It is a requirement of current wind turbines have a useful life of twenty years. It is therefore required that mechanical systems have a long life, which requires a proper maintenance of hydraulic and lubrication oils. This implies changing the oil at time intervals predetermined due to degradation of its properties.

Changing the oil outdoors is expensive and It always represents an ecological risk. Limit the number of changes of oil or eliminate them completely in the twenty years of useful life of the machine results in a considerable reduction of maintenance costs and ecological risk.

Given that the number of wind farms is going on the increase, the advantages of limiting or eliminating oil changes acquire, now and in the future, sum importance.

Oil degradation in turbines wind power is mainly due to two factors: oxidation and water contamination. Additional factors such as deformation viscose of the oil chain molecules, which causes a viscosity reduction over time, they have a much less influence on the properties of the oil and, in the case of some oils, are invaluable. Arc effect electrical due to electrostatic discharge or leakage current it can be considerable in some cases and favor the oxidation of oil and varnish formation. The presence of oxygen in the atmosphere in contact with oil is also a factor that It greatly contributes to triggering this process.

The removal of oxygen and moisture from the atmosphere in contact with the oil, and its replacement by gases inert, will result in the suppression of phenomena before described, so that the life of the oil will be extended considerably. The object of this invention is to provide a system to achieve that goal. Ultimately, with the system of the present invention, a suitable formulation of the oils, appropriate filtering systems and procedures maintenance, it is possible to have a turbine multiplier wind, or a hydraulic system, "lubricated for life".

This would represent a considerable improvement. regarding current technology in terms of ecological risks and maintenance costs, especially in the case of turbines wind farms installed on the high seas. It can also be a factor. important when making possible the use of vegetable oils biological and biodegradable susceptible to hydrolysis and a faster degradation, in wind turbines.

Brief Summary of the Invention

Oil systems are made up, so general, of a main tank for oil storage, one or more pumping systems connected to said reservoir, systems in-line filtration with said pumps and oil circuits to through which the oil circulates before returning to the tank principal. These circuits include pipes, purge valves, filters and internal ducts of the operating devices mechanic. Except for the connection of the main tank to the pumps, the called the intake side of the pump, which can operate at a pressure lower than atmospheric, the rest of the circuits operate at a higher or slightly higher pressure than the atmospheric pressure. These intake sides of the pumps are well sealed and the air cannot penetrate these areas in the oil system It is in the space above the level of the oil in the main tank and inside the devices, such as turbine multipliers wind farms, where the vents are located through which the oil is exposed to oxygen and moisture.

In the present invention said vents are permanently closed or have an opening valve which can only be opened in a controlled manner when they are met Certain special conditions.

In the present invention, the air space located above the oil in the main tank or within device housings such as the multiplier, are connect, where appropriate, to a source of inert gas, such as nitrogen, argon, other noble gases, CO2 or mixtures thereof, through a control valve The pressure in said space above of the oil is always kept slightly higher than the pressure atmospheric so that the air cannot enter it and it guarantee the presence of inert gas. This pressure should be, preferably, between 0.1 and 0.3 bar higher than the barometric. Any leak that occurs through the joints of the aforementioned devices are corrected by a control valve that allows the entry of more inert gas into the free space and thus maintains the preset pressure. The source of inert gas can be a tank or tank, pressurized at high pressure to get to store a large volume of inert gas, or any other source, such as cryogenically maintained liquid gas or a plant of production of inert gas that is inside, or in the proximity of the wind turbine facilities. Anyone of the aforementioned sources of inert gas, whether they are cylinders to high pressure, cryogenic cylinders or gas production plants inert, they are already available in the market and are used in a way usual in tire inflation systems, welding, clinics and medical centers. Since these sources They are available with different levels of capacity, they will be maintenance objectives of the head of the wind turbine that determine which one should be used in this case.

A gas producing plant may be advisable, mainly, for offshore installations that have very long maintenance periods, perhaps several years, and have seawater to cover the cooling needs of some such plants. A large pressurized tank may be sufficient for the maintenance periods of an offshore installation to be several years, since the loss of gas through the joints is considered quite
reduced

Each time the pressure inside said tank or deposit falls below a predetermined value that is considered close to gas depletion, a signal of warning indicating that it is necessary to replace said cylinder gas.

This creates a permanent inert and artificial atmosphere above the oil that prevents it come into contact with oxygen and moisture. The space located on top of the oil it can be drained of air during the assembly of the machine and refill with inert gas, or not. On this last case, over time the dilution of the air will occur, since the air that leaking from the joints of the devices in operation it replace with corresponding amounts of inert gas. This takes place over prolonged periods of time, since the Leakage rate through those mentioned together is very small. It can achieve a shortening of the dilution time by opening a additional discharge valve that communicates the air above of the oil with the outside atmosphere in order to create a leak controlled higher volume with positive pressure difference preset in the device and the external barometric pressure.

A feed valve connects the mentioned inert gas source, an example of which can be a tank, with the air space above the oil inside the device of work, and releases said inert gas in a controlled manner. A plurality of pressure sensors (or at least one) measure continuously the pressure in said air space and the value obtained is compared with barometric pressure. When the difference between the two is below a predetermined value, the said feed valve opens automatically until the Free space pressure regains the desired level. Valves and the pressure sensors can be connected to a control module that It can be programmed to control the valve opening power and to open an emergency valve that allows discharge the gases from the air space above the oil in in case the pressure in it exceeds a preset value.

The control system can generate a signal of warning when the pressure in said free space is equal or lower than atmospheric pressure for a period of time predetermined. This would mean that there has been a possible air pollution You can also install sensors oxygen and moisture in said free space above the oil a so that any contamination is detected and a signal is emitted Warning

In a simple embodiment of this invention, The system includes a mechanical feed valve that detects the pressure difference between the air gap and the pressure atmospheric The said valve is designed to open when the difference between free space pressure and pressure atmospheric is below a first positive value predetermined, connect said free space with the gas source inert, and close when the aforementioned pressure difference is due to above a second higher default positive value. A second mechanical ventilation valve that detects said pressure difference is designed to open when said pressure difference is higher than a third positive value, connect the free space with the atmosphere, and close when the pressure difference is equal to or less than a fourth value lower positive.

Brief description of the drawings

Figure 1 is a schematic representation of a wind turbine showing a multiplier with a crankcase of oil connected, for the sake of generalization, to a tank of independent oil, and the main elements of the system control of the atmosphere in contact with the oil.

Figure 2 is a schematic representation of a wind turbine that shows an alternative location of the inert gas source.

Figure 3 is a schematic section of the upper half of a sealing arrangement of an axis of the multiplier

Detailed description of the invention

As shown in Figure 1, the rotor of a wind turbine drives a multiplier "G", whose axis transmission is connected to a load, such as a generator "A".

The "H" tank of the multiplier Store the lubrication oil inside the multiplier. A second storage tank "K" can be connected to the said first reservoir through a sealed atmosphere conduit outside and that supplies the excess oil from said tank internal "H" to the second deposit "K", either by gravity or well with the help of a pump (not shown for major simplicity). The oil of both deposits is therefore under the Same atmospheric environment and at the same pressure level.

A source of inert gas located in the gondola, such as the "T" tanks, it is connected through a pressure reducing valve "R", to a second chamber of expansion "J" which, through another reducing valve of pressure "P", is connected to the inert gas chamber located on the oil of the multiplier "G". In this way, in if the pressure in the inert gas source is high, the low pressure reduction of free space above the Oil multiplier is done in two phases. In general, this two-phase system may not be necessary and a single single phase, depending on the volume of said free space above of the oil and of the limits established for the variation of pressure in that space.

The "P1" and "P2" pumps driven by "M" engines, force the circulation of oil through the radiators "C1" and "C2" and through the system of lubrication of the work device, a multiplier in this case. Auxiliary equipment, such as filters, thermal valves, valves bypass and unidirectional valves, among other elements, not Shown here for simplicity. However, the oil that is downstream of said circulation pumps is at a pressure higher than atmospheric and, therefore, does not exist possibility of air pollution. The side pipes suction and ducts of the aforementioned pumps, which can work at a lower atmospheric pressure, they remain as short possible and all the accessories and the primary pump shaft are properly sealed to avoid any possible contamination with the air.

The breathing tube assembly "L" is it consists of at least two branches; the first one can open at atmosphere through a "V" bypass valve and used to evacuate the air each time the device, while the second branch is connected to a filter air purge and drying set "E" that closes via valve "B", which is normally closed. The valve "B" can be opened automatically remotely when the pressure inside the device exceeds a maximum level default or when the system does not work due to some failure, or if you decide to put the device in the mode of operation with air ventilation.

Oxygen sensors can be incorporated "X" and humidity "N" to control the purity of the gas inert inside the device; these sensors can be connected to a system control module to determine if it has produced air pollution.

Pressure sensor "U" monitors continuously the pressure inside the work device that, connected to the system control module, it allows to emit a signal to open the "R" and "P" valves when the difference in this barometric pressure is below a value default so that within the device the cited default pressure difference value, or to emit a warning signal when said internal pressure is maintained below barometric pressure for a period of time predefined

Pressure gauge "I" monitors continuously the pressure inside the said inert gas tank at in order to determine when the stored gas is about to run out; This indicator can be electrically connected to a module control to issue a warning signal indicating that said Deposit must be replaced or recharged. One is provided plurality of "CH" bypass valves in series, and at least one, at the point of discharge of the inert gas source "T" for allow the isolation of said source and its replacement or recharge

With respect to figure 2, a wind turbine installation in which the aforementioned gas source inert "Z" is located at the bottom of the tower. A duct "W" extends along the tower and enters inside from the gondola, where it connects to the air space located inside of the work device. Pressure reducing valve "R" reduces the pressure of the said inert gas source and the indicator pressure "I" continuously monitors the state of charge of the inert gas source "Z".

In another embodiment of this invention, with respect of figures 1 and 2, the sources of inert gas "T" and "Z" may include an "O" inert gas production plant and a Tank or storage tank. These plants producing inert gas, examples of which are nitrogen generators cryogenic, adsorption by pressure and membrane changes of separation, are available in the market with different capacities and can be powered with electric power or with others media, such as an internal combustion engine or solar panels, between others. Due to the reduced gas consumption planned for this invention, a single generator may be sufficient to feed several wind turbines that can be connected to it through ducts.

With respect to figure 3, it is represented, by way of for example, the upper half of a cross section longitudinal of a construction shaft sealing arrangement standard. The hermetic seal on the left side prevents leakage of inert gas from inside said working device. The arrows located above the sealing edge of said seal hermetic represent the pressure that the internal inert gas exerts on said edge to improve the sealing action of the spring of metal. The hermetic seal on the right side prevents the entrance of the external air inside said working device during the process of evacuation of air prior to loading the inert gas. This meeting may be temporary and may be removed after evacuation and load of said work device.

It is understood that the present disclosure is a description in general terms of the invention and is merely illustrative of the preferred embodiments, and that the number, design or types of components do not imply any limitation, either in in terms of size, shape, proportions, geometry or design, of system.

Claims (8)

1. Wind turbine multiplier with controlled atmosphere composed of at least one tank where a lubrication oil is stored in contact with a gas, and a set of sensors inside and outside the tank connected to a control module that monitors the data of said sensors and coordinates the activation of a set of valves characterized in that it has a power supply (T, Z, O) that injects an inert gas into the tank at a pressure higher than atmospheric pressure, a controlled opening vent (L) , a set of gas pressure sensors (U), a set of gas sealing gaskets, a set of oxygen sensors (X), a set of humidity sensors (N), and a set of mix detector detectors gases lodged inside the tank. 2. Wind turbine multiplier with controlled atmosphere according to claim 1 characterized in that the power supply (T, Z, O) injects a pressurized gas into the tank when a decrease in barometric pressure is detected inside the tank of the order of 0.1 -0.3 bar compared to atmospheric pressure, this value being preferably 0.1 bar. 3. Wind turbine multiplier with controlled atmosphere according to claim 1 characterized in that the gas that introduces the power supply into the tank is an inert gas such as nitrogen, noble gases or a mixture thereof. 4. Wind turbine multiplier with controlled atmosphere according to claim 1 characterized in that the feeding device consists of a set of tanks (T) where pressure gases or mixtures of pressurized gases are stored, connected to a set of regulating valves (R, P) that they are activated by the control module and that they inject the gas into an expansion chamber (J) and then into the tank at a preset pressure. 5. Wind turbine multiplier with controlled atmosphere according to claim 1 characterized in that additionally the feeding device includes an inert gas (O) production plant. 6. Wind turbine multiplier with controlled atmosphere according to claim 1 characterized in that it has a controlled opening vent (L), a set of gas pressure sensors (U), a set of oxygen sensors (X), a set of sensors of humidity (N), and a set of detectors of gas mixtures connected to the control module that automates the process of injection of pressurized gas into the tank. 7. Wind turbine multiplier with controlled atmosphere according to claim 1 characterized in that the vent (L) comprises a first air evacuation circuit, and a second circuit connected to a purge filter and a drying assembly (E) generally closed by valves (V, B) connected to the control module. 8. Wind turbine multiplier with controlled atmosphere according to claim 1 characterized in that the valve (B) dislodges the gas in a controlled manner when the barometric pressure inside the tank exceeds a certain value in the range of 0.3-0.8 bar atmospheric pressure, and It closes when the pressure inside the tank returns to preset values.