Abstract:
The present invention concerns a wind power installation, in particular a wind power installation having an apparatus for the dehumidification of a gaseous medium in a substantially closed space within the wind power installation. In order to keep down the personnel and logistical expenditure for attaining proper operability of the apparatus, to simplify the structure and to permit very substantially maintenance-free operation, the apparatus includes a first air exposed element and a cooling device for cooling the first element to a temperature below the ambient temperature.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention concerns a wind power installation, in particular a wind power installation having an apparatus for dehumidifying a gaseous medium in a substantially closed space within the wind power installation.  
         [0003]     2. Description of the Related Art  
         [0004]     A dehumidifying apparatus operating on a chemical basis has long been known. In that known apparatus moisture is removed from the ambient air chemically and the moisture is collected in a catch container. That known apparatus however suffers from the disadvantage that the chemical has to be replaced at certain time intervals in order to maintain proper operability of the apparatus. In relation to a large number of apparatuses which are to be centrally monitored and maintained, that requires additional expenditure in terms of personnel and logistics.  
         [0005]     Dehumidifiers are also known, in which an enclosed space is cooled on the basis of the operative principle of a refrigerator by way of a compressor/evaporator unit by means of a coolant specifically provided for that purpose, in order in that way to remove moisture from the air contained in that space.  
         [0006]     With those apparatuses however the structure is complicated and expensive and in addition it is necessary for the cooling fluid to be collected separately upon disposal.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     Therefore the object of the present invention is to develop a wind power installation and in particular to design a wind power installation in such a way that moisture problems within the wind power installation can be eliminated in a simple manner.  
         [0008]     That object is attained by a wind power installation having the features of claim  1 . Advantageous developments are set forth in the appendant claims. In the wind power installation according to the invention the object is attained by a first flat or air exposed element and a cooling device for cooling the element to a temperature below the ambient temperature (room temperature). At that ambient temperature a part of the moisture contained in the air condenses at the surface of the first element. That moisture is removed from the ambient air in that way and can be drained off.  
         [0009]     In order to permit maintenance-free long-term operation the cooling device is preferably a Peltier element or a group of Peltier elements which withdraw heat from the first element and thereby cool that element. The heat which is withdrawn from the first element is discharged to the ambient atmosphere again by way of a second element.  
         [0010]     In order to achieve a particularly good effect the second element can be connected to a wall delimiting the space to be dehumidified or can even be formed by that wall.  
         [0011]     The condensate water can be discharged into the open through a duct and a wall opening. In that case the wall opening can preferably be provided in the region of the ground in order to avoid traces of dripping water on outside walls.  
         [0012]     In order to prevent the condensate water from uncontrolledly dripping down within the space in the event of a blockage of the duct for draining off the condensate water, it is possible to provide a container which catches those drips. Thus the container can be emptied in the context of an inspection procedure or after signalling from a sensor suitably arranged in the container. At the same time the closure of the duct can be removed so that the condensate water is again automatically removed from the space.  
         [0013]     In a particularly preferred development of the invention there is provided a first temperature sensor for detecting the temperature of the first element and a second temperature sensor for detecting the ambient temperature. The apparatus according. to the invention can be controlled by means of those sensors and a control device connected on the output side thereof, in such a way that the first element is always at a predeterminable temperature difference with respect to the ambient temperature. A constant dehumidification output can be achieved in that way.  
         [0014]     Advantageous embodiments are recited in the appendant claims.  
         [0015]     Room air dehumidifiers are already known from DE-U-92 10 970.5, DE 44 23 851, German patent specification No 1 189 250, EP 0 758 730 A2 and U.S. Pat. No. 5,071,027. The use of such room air dehumidifiers within wind power installations has hitherto not been proposed. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)  
       [0016]     An embodiment of the invention is described in greater detail hereinafter with reference to the drawings in which:  
         [0017]      FIG. 1  shows a perspective view of an apparatus according to the invention,  
         [0018]      FIG. 2  shows a further view of the apparatus according to the invention,  
         [0019]      FIG. 3  shows an arrangement of an apparatus according to the invention in the pylon of a wind power installation, and  
         [0020]      FIG. 4  shows a perspective view of an apparatus according to the invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     Referring to  FIG. 1  shown therein is a side view of an apparatus according to the invention. Disposed between a first element  10  and a second element  14  is a cooling device  12 . The cooling device  12  is a Peltier element operated with electrical power or a group of Peltier elements. It causes transportation of heat from a lateral boundary surface to the other—in this case the heat is transported from the first element  10  to the second element  14 .  
         [0022]     If the cooling device  12  is acted upon by a suitable current which is predetermined in respect of amount and direction, heat is withdrawn from the first element  10  and transported to the second element  14  where it is in turn discharged to the ambient atmosphere. The first element  10  and the second element  14  are preferably in the form of cooling bodies, that is to say flat or air exposed aluminium elements with cooling ribs extending thereon for increasing the effective surface area.  
         [0023]     Due to the extraction of heat the first element  10  cools down to below the ambient temperature and the moisture contained in the ambient air condenses at the element  10 .  
         [0024]     As the surface area-increasing cooling ribs of the first element  10  extend vertically, the condensate water can easily drain away downwardly due to the effect of the force of gravity and can be suitably collected up and if necessary drained off by means of conduits.  
         [0025]     It can be seen from the side view in  FIG. 2  that the condensate water which drains off downwardly along the cooling ribs of the first element  10  passes into a duct  20  which is passed into the open air through a wall  32  so that the condensate water can drain off into the open without any problem.  
         [0026]     If that duct  20  should suffer from a blockage, there is additionally provided a catch space  22  which can store the condensate water so that it does not drip uncontrolledly into regions below the apparatus. Provided in that catch space  22  is a liquid sensor  24  which can detect a rise in the level of liquid and trigger a suitable signal which for example can be used to cause maintenance personnel to remove the closure of the duct  20  and empty the catch space.  
         [0027]     The apparatus has a control device  26  in order to detect the temperature of the first element  10  by way of a first temperature sensor  16 . The ambient temperature is detected by way of a second temperature sensor  18 . The control device  26  can then derive the required control effect for the cooling device  12 , from the temperature difference and predetermined reference values. It will be appreciated that this control system can also monitor the liquid sensor  24  and produce and output the corresponding signals.  
         [0028]      FIG. 3  shows a partial view of a pylon  30  of a wind power installation. The apparatus according to the invention which in  FIG. 3  is identified generally by reference numeral  2  is assumed to be arranged approximately at a halfway position on the height of the pylon  30 . The duct  20  for draining off the condensate water is laid within the pylon  30  to a position close to the ground in  FIG. 3  and only there issues outwardly through the wall  32  of the pylon  30 . In one embodiment, the second element  14  which receives the heat in directly coupled to the wall  32  of the pylon  30 , or in one case, is composed of the wall  32  itself, so that a large heat sink mass is provided to assist in the cooling element  10  to become very cool easily and without having to heat the element  14  itself to a high temperature. Namely, the mass of element  14  for receiving the heat which is removed from the cooling element  10  can be very large so that the element  10  can easily become very cool and not cause a corresponding temperature rise in the element  14  which receives the heat. That reliably prevents traces of water on the outside of the wall  32 .  
         [0029]     The preferred position of installation of the dehumidifier according to the invention is in the region of the base of the tower, but installation at other locations on the wind power installation is also possible. The region of the base of the tower has the advantage that air which has already been dehumidified will pass through the rectifiers which are usually arranged in the base of the tower.  
         [0030]     A further advantageous possible way of draining off the condensate water from the tower is in the region of the access door. The door is fitted in any case as a separate component element into the lower section of the pylon. It is possible in that way to avoid a change in structure which is essential when making an opening through the wall of the pylon.  
         [0031]      FIG. 4  shows a modified representation of  FIG. 1 . The difference in relation to  FIG. 1  essentially lies in a baffle plate  40  which is arranged above the cooling body (first and second element)  10 ,  14  and which deflects cooled air which is guided along the first (cooling) element by a fan. That cooled air is deflected on to the second (warm) element  14  by the baffle plate  40  and cools the second element. In that arrangement the baffle plate  40  is held in a predetermined position by supports  42 . For the sake of clarity of the drawing only one support  42  is illustrated, but of course others support will be provided as needed.  
         [0032]     Accordingly, heat is extracted at the first element  10  from the air flowing therepast, and that heat is transported to the second element  14  by the cooling device, usually a (Peltier element)  12 . The baffle plate  40  deflects the cooled air to the second element  14  and there the air picks up again the heat (previously extracted from it). In that way the fan power required for cooling the second element  14  and thus the power consumption of the apparatus can be reduced.  
         [0033]     As described, the function of the cooling device, such as for example the Peltier element is therefore as a primary matter not cooling of the air within the wind power installation but solely dehumidification of the interior of the installation, for which reason also the cooled air is deflected from one side of the cooling device to the other and is then equally warmed again and the temperature in the installation is thus scarcely affected.