wind turbine generator with a heat exchanger

Abstract

The present invention relates to a wind turbine generator with a heat-generating source, e.g. a generator or a gear-box. A primary and a secondary cooling circuit, arranged for circulating a first and a second fluid, respectively between the heat-=generating source and a heat exchanger, and a cooling reservoir and the heat exchanger, respectively. The heat exchanger comprises a plurality of pipes for conveying the second fluid from the secondary cooling circuit through the heat exchanger, the plurality of substantially parallel pipes being arranged for heat exchange with a flow of the first fluid from the primary cooling circuit. The secondary cooling circuit further comprises a dispersion chamber connected to the plurality of pipes, the dispersion chamber having a fluid intake being positioned sideways relative to the plurality of pipes so as to provide, at least partly, a levelling of the flow distribution across the plurality of pipes of the second fluid prior to heat exchange. The invention provides an improved and more compact heat exchanger due to the more uniform flow distribution of the second fluid.

1 . A wind turbine generator comprising;
 a heat-generating source,   a primary cooling circuit, the primary cooling circuit being a closed cooling circuit arranged for circulating a first fluid between the heat-generating source and a heat exchanger,   a secondary cooling circuit, the secondary cooling circuit being arranged for intake of a second fluid into the heat exchanger,   wherein the heat exchanger comprises a plurality of pipes for conveying the second fluid from the secondary cooling circuit through the heat exchanger, the plurality of substantially parallel pipes being arranged for heat exchange with a flow of the first fluid from the primary cooling circuit, and   wherein the secondary cooling circuit further comprises a dispersion chamber connected to the plurality of pipes, the dispersion chamber having a fluid intake being positioned sideways relative to the plurality of pipes so as to provide, at least partly, a levelling of the flow distribution across the plurality of pipes of the second fluid prior to heat exchange.   
     
     
         2 . A wind turbine generator according to  claim 1 , wherein the dispersion chamber is arranged for diverting the second fluid from a first flow direction, which is non-parallel to plurality of pipes, and into a second flow direction which corresponds to the direction of the plurality of pipes. 
     
     
         3 . A wind turbine generator according to  claim 1 , wherein the plurality of pipes is substantially orthogonal arranged to, at least a part of, the flow (P 1 , P 2 , P 3 ) of the first fluid through the heat exchanger. 
     
     
         4 . A wind turbine generator according to  claim 1 , wherein a cross-section of the plurality of pipes, orthogonal to the flow direction, forms a shape spanned by two dimensions having un-even lengths, the intake of the dispersion chamber being positioned next to the shortest of the two dimensions. 
     
     
         5 . A wind turbine generator according to  claim 4 , wherein the flow direction of the second fluid prior to entering the pipes is substantially along the longest of the two dimensions. 
     
     
         6 . A wind turbine generator according to  claim 1 , wherein the said fluid intake is positioned outside of a direct flow direction corresponding to the orientation of the plurality of pipes. 
     
     
         7 . A wind turbine generator according to  claim 6 , wherein the said fluid intake is further oriented substantially parallel to the said plurality of pipes, the flow through the second circuit thereby forming a substantially orthogonal flow pattern prior to intake into the plurality of pipes of the heat exchanger. 
     
     
         8 . A wind turbine generator according to  claim 1 , wherein the inlet of the primary cooling circuit into the heat exchanger is located in an opposite position relative to the outlet of the primary cooling circuit from the heat exchanger with respect to the dispersion chamber. 
     
     
         9 . A wind turbine generator according to  claim 1 , wherein the first and/or the second fluid are/is comprised in a group of: air, an inert gas, and a cooling liquid. 
     
     
         10 . A wind turbine generator according to  claim 1 , wherein the second fluid is a gas being forced through the secondary cooling circuit by gas motion means. 
     
     
         11 . A wind turbine generator according to  claim 1 , wherein a mean ratio (F) between an inter-distance (L_c) between the plurality of pipes and a diameter (D_O) of the pipe is in the interval from approximately 1.1 to approximately 1.4, or in the interval from approximately 1.2 to approximately 1.3. 
     
     
         12 . A method for cooling a heat-generating source in a wind turbine generator, the method comprising:
 providing a primary cooling circuit, the primary cooling circuit being a closed cooling circuit arranged for circulating a first fluid between the heat-generating source and a heat exchanger, and   providing a secondary cooling circuit, the secondary cooling circuit being arranged for intake of a second fluid into the heat exchanger,   wherein the heat exchanger comprises a plurality of pipes for conveying the second fluid from the secondary cooling circuit through the heat exchanger, the plurality of substantially parallel pipes being arranged for heat exchange with a flow of the first fluid from the primary cooling circuit, and   wherein the secondary cooling circuit further comprises a dispersion chamber connected to the plurality of pipes, the dispersion chamber having a fluid intake being positioned sideways relative to the plurality of pipes so as to provide, at least partly, a levelling of the flow distribution across the plurality of pipes of the second fluid prior to heat exchange.