Patent Publication Number: US-2022213874-A1

Title: Cooling device, motor, and wind turbine set

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a National Stage of International Application No. PCT/CN2020/078431, filed on Mar. 9, 2020, which claims priority to Chinese Patent Application No. 201910364180.4 entitled “COOLING DEVICE, MOTOR, AND WIND TURBINE SET” filed on Apr. 30, 2019, both of which are incorporated herein by reference in their entireties. 
    
    
     FIELD 
     The disclosure relates to a technical field of cooling, and in particular to a cooling device, a motor, and a wind turbine set. 
     BACKGROUND 
     Wind power is one of the renewable energy technologies which are the closest technologies to commercialization, and is the focus of renewable energy development. A motor in the wind turbine set has heat loss during operation, which mainly includes electromagnetic loss, that is, Joule heat generated in the winding due to ohmage, that is, copper loss; hysteresis loss, eddy current loss, or the like in an iron core, that is, iron loss; inevitable stray loss; and also magnetic steel loss if it is a permanent magnet motor. These losses cause the motor to release a large amount of heat when it is in operation, and the heat will not only cause a certain impact on the motor itself and its insulation structure, which leads to shortened insulation life and even failure insulation, but also cause the output power of the motor to drop continuously. 
     With the rapid development of offshore wind turbine set, the single set capacity of the set continues to increase, which directly leads to the continuous increase in the loss of the wind turbine set and leads to the cooling system of the motor to occupy larger space in the nacelle. For working conditions with heavy wind and sand or harsh working environment, especially for offshore salt spray environment, the air-air cooling system is likely to cause dust accumulation in the turbine and decrease in the cooling air volume of the system, which results in insufficient heat dissipation, and more likely to cause damage and failure of components, which reduces the life of the whole machine; and if a water cooling system is adopted, in order to ensure the winding temperature limit, requirement on temperature rise, and temperature uniformity, it is necessary to dispose too many circuits and joints in the motor, the compact flow channel also causes the increase of system resistance and self-consumption, and an air cooling system is also required independently considering the cooling of the ends of the winding and the rotor, thereby resulting in a complicated structure of the and reducing the reliability. 
     SUMMARY 
     The object of the present application is to provide a cooling device, a motor, and a wind turbine set, and the cooling device has a simple and compact overall structure and occupies a small space. 
     In an aspect, the present application proposes a cooling device, which is integrated inside the motor, and the cooling device includes a housing extending along an axial direction of the motor, wherein the housing has a receiving cavity and an air inlet and an air outlet in communication with the receiving cavity, and the housing is in communication with an interior of the motor through the air inlet and in communication with ventilation chambers at two axial ends of the motor through the air outlet; a heat exchanger located in the receiving cavity and provided close to the air outlet; and a circulation fan provided in the receiving cavity along the axial direction of the motor. 
     In another aspect, the present application further proposes a motor, the motor includes a stator support and a rotor support, which are connected in a dynamic sealed manner to form ventilation chambers at two axial ends of the motor, and the motor further includes a confluence chamber provided along a circumferential direction of the stator support; and at least one cooling device of any type as above described distributed at intervals along the circumferential direction of the stator support, wherein the cooling device is located on a radial inner side of the confluence chamber and in communication with the confluence chamber through the air inlet. 
     In another aspect, the present application also provides a wind turbine set, which includes a nacelle; any one motor as above described, wherein a circulation fan of a cooling device of the motor is provided on a side of the nacelle. 
     By providing the heat exchanger and the circulation fan in the housing extending along the axial direction of the motor, the cooling device provided by the present application can realize a modular design of the cooling device, has a simple and compact structure, and occupies a small space. By providing a confluence chamber and at least one cooling device along the circumferential direction of the stator support, the motor provided by the present application can cool the heating components inside the motor in circulation, has a simple and compact overall structure, so the heat dissipation is uniform. In addition, by adopting the motor, the wind turbine set provided by the present application can effectively reduce the size of the nacelle, therefore reducing the whole machine cost and load and improving the reliability and maintainability of the wind turbine set. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present application can be better understood from the following description of the specific embodiments of the present application in conjunction with the accompanying drawings, wherein by reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects, and advantages of the present application will become more apparent, and the same or similar reference numbers indicate the same or similar features. 
         FIG. 1  is a schematic view of an exploded structure of a cooling device provided by an embodiment of the present application; 
         FIG. 2  is a schematic view of a structure of a housing in the cooling device shown in  FIG. 1 ; 
         FIG. 3  is a schematic view of an overall layout structure of a motor provided by an embodiment of the present application; 
         FIG. 4  is a perspective view of a partial structure of the motor shown in  FIG. 1 ; 
         FIG. 5  is a schematic view of a partial structure of the motor shown in  FIG. 4  along an axial direction; and 
         FIG. 6  is a cross-sectional view taken along a direction A-A in  FIG. 5 . 
     
    
    
     DESCRIPTION OF REFERENCE NUMBERS 
       10 —cooling device;  11 —heat exchanger;  111 —first joint;  112 —second joint;  12 —circulation fan;  13 —housing;  130 —receiving cavity;  1301 —air inlet;  1302 —air outlet;  131 —first plate;  132 —second plate;  133 —third plate;  134 —fourth plate;  135 —installation groove;  136 —inspection opening;  14 —liquid supply pipe;  15 —liquid/air return pipe;  16 —cover plate;  161 —first opening;  162 —second opening; 
       1 —main shaft;  1   a —stator winding;  1   b —stator core;  1   c —air gap;  1   d —radial channel; 
       20 —stator support; a—ventilation hole;  21 —annular plate;  22 —separation plate;  23 —ventilation pipe;  24 —filter;  25 —confluence chamber;  26 —first end plate;  27 —second end plate; 
       30 —rotor support;  3   a —magnetic steel;  31 —ventilation chamber; 
       100 —motor;  200 —wheel hub;  210 —impeller;  300 —nacelle. 
     DETAILED DESCRIPTION 
     The features and exemplary embodiments of various aspects of the present application will be described in detail below. Many specific details are disclosed in the following detailed description in order to fully understand the present application. However, it is obvious to those skilled in the art that the present application can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application. The present application is by no means limited to any specific configurations and algorithms proposed below, but covers any modification, replacement, and improvement of elements, components, and algorithms without departing from the gist of the present application. In the drawings and the following description, well-known structures and technologies are not shown in order to avoid unnecessary obscurity of the present application. 
     In order to better understand the present application, a cooling device, a motor, and a wind turbine set provided by the embodiments of the present application will be described in detail below in conjunction with  FIGS. 1 to 6 . 
     With reference to  FIG. 1 , an embodiment of the present application provides a cooling device  10  integrated inside a motor and including a heat exchanger  11 , a circulation fan  12 , and a housing  13 . 
     The housing  13  extends along an axial direction of the motor, has a receiving cavity  130  and an air inlet  1301  and an air outlet  1302  in communication with the receiving cavity  130 , and is in communication with an interior of the motor through the air inlet  1301  and in communication with ventilation chambers located at two axial ends of the motor through the air outlet  1302 . 
     The heat exchanger  11  is located in the receiving cavity  130  and provided close to the air outlet  1302 , and the circulation fan  12  is provided in the receiving cavity  130  along the axial direction of the motor. 
     The heat exchanger  30  may be an air-air or air-liquid heat exchanger. Optionally, the heat exchanger  30  is, for example, but not limited to, a plate-fin, tube-fin, and tubular air-liquid heat exchanger, and the cooling medium in the heat exchanger  30  may be a liquid medium or a phase change medium, and exchanges heat with an external cooling system through a liquid supply pipe  14  and the liquid/air return pipe  15  located outside of the housing  13  to further cool the motor in circulation. 
     Under the action of the circulation fan  12 , the cooling air enters the ventilation chambers at the two axial ends of the motor through the air outlet  1302 , flows through a heating component inside the motor, and then enters the housing  13  through the air inlet  1301  to exchange heat with the heat exchanger  11 . 
     By providing the heat exchanger  11  and the circulation fan  12  in the housing  13  extending along the axial direction of the motor, the cooling device  10  provided by the embodiments of the present application can realize a modular design of the cooling device  10 , has a simple and compact structure, occupies a small space, and may be applied to various devices and apparatus, a motor or the like, that require heat dissipation. 
     With reference to  FIG. 2 , the housing  13  includes a first plate  131  and a second plate  132 , which are provided opposite to each other along the axial direction of the motor, the air inlet  1301  is provided on the second plate  132 , and an end of the circulation fan  12  along its own axial direction projects beyond the first plate  131 . 
     The housing  13  further includes a third plate  133  and a fourth plate  134 , which are connected to the first plate  131  and the second plate  132  and provided opposite to each other, and an air outlet  1302  is formed by the first plate  131 , the second plate  132 , the third plate  133 , and the fourth plate  134  at at least one circumferential end of the motor. For example, the air outlet  1302  may be formed at two circumferential ends of the motor. 
     Optionally, the third plate  133  and the fourth plate  134  are provided with installation grooves  135  at the two circumferential ends of the motor, the two heat exchangers  11  are detachably installed in the installation grooves  135  of the third plate  133  and the fourth plate  134 , and the circulation fan  12  is provided between the two heat exchangers  11 , thereby increasing the heat exchange area. 
     In addition, the first plate  131  is provided with an inspection opening  136  allowing the heat exchanger to pass through, and the first plate  131  covers the inspection opening  136  via a cover plate  16 . For example, a sealing ring or the like is provided between the cover plate  16  and the inspection opening  136 . 
     A first joint  111  and a second joint  112  are provided on the heat exchanger  11 , the cover plate  16  is provided with a first opening  161  and a second opening  162 , the first joint  111  projects beyond the first opening  161  and is connected to the liquid supply pipe  14 , and the second joint  112  projects beyond the second opening  162  and is connected to the liquid/air return pipe  15 . 
     Therefore, when the heat exchanger  11  needs to be replaced or repaired, it is only necessary to remove the cover plate  16  and pull the heat exchanger  11  along an extension direction of the installation groove  135 , and thus the replacement work can be quickly completed at the inspection opening  136  without removing other components, thereby improving the maintainability of the cooling device  10 . 
     With reference to  FIGS. 3 to 6 , an embodiment of the present application also provides a motor, the motor includes a stator support  20  and a rotor support  30 , which are connected in dynamic sealed manner to form ventilation chambers  31  at two axial ends of the motor, and the motor further includes a confluence chamber  201  and at least one cooling device  10  of any one type as described above. 
     The motor can be a structure having an outer rotor and an inner stator or a structure having an outer stator and an inner rotor. The stator is fixed on a fixed shaft by the stator support  20 , the rotor is fixed on the moving shaft by the rotor support  30 , and the fixed shaft and the moving shaft are connected by a bearing to realize relative rotation. The fixed shaft and the moving shaft together constitute a main shaft  1  of the motor. For ease of description, the description is made in the embodiments of the present application by taking a motor of a structure having the outer rotor and the inner stator as an example. 
     The stator includes a stator winding  1   a  and a plurality of stator cores  1   b  provided at intervals along the axial direction, and a radial channel  1   d  is formed between every two adjacent stator cores  1   b . Each of the stator cores  1   b  includes a yoke part and a tooth part (not shown in the figure) which is integrally formed with the yoke part, the stator winding  1   a  is wound around the tooth part, and the stator is fixed to the stator support  20  by the yoke part. The rotor support  30 A is provided with a magnetic steel  3   a  thereon, and an air gap  1   c  is formed between the rotor and the stator along the radial direction. The stator winding  1   a , the stator cores  1   b , and the magnetic steel  3   a  are all heat dissipating components. 
     The confluence chamber  201  is provided along the circumferential direction of the stator support  20 , at least one cooling device  10  is provided along the circumferential direction of the stator support  20 , and the cooling device  10  is located on a radial inner side of the confluence chamber  201  and in communication with the confluence chamber  201  through the air inlet  1301 . 
     Thus, the cooling process of the cooling device  10  provided by the embodiments of the present application is as follows: under the action of the circulation fan  12  in the cooling device  10 , the cooling air is introduced from the interior of the motor through the ventilation pipe  23  into the housing  13  of the cooling device  10  such that the heated cooling air exchanges heat with the heat exchanger  11 , as shown by the arrow W 3  in  FIG. 2 , the heat exchanger  11  is connected to the external cooling system through the liquid supply pipe  14  and the liquid/air return pipe  15  such that the temperature of the cooling air drops to form an airflow with relatively low temperature, and under the negative pressure of the circulating fan  12 , a part of the cooling air directly enters the adjacent ventilation chamber  31  at one end, as shown by the arrow W 1  in  FIG. 4 , to cool one end of the stator winding  1   a  and then flows along the air gap  1   c  to realize the cooling of a part of the magnetic steel  3   a , the rotor yoke, and the stator winding  1   a ; and the other part of the cooling air enters the ventilation chamber  31  at the other end of the motor through a ventilation hole a on a separation plate  22 , as shown by the arrow W 2  in  FIG. 2 , to cool the other end of the stator winding  1   a  and then flows along the air gap  1   c  to realize the cooling of the other part of the magnetic steel  3   a , the rotor yoke, and the stator winding  1   a.    
     The two parts of cooling air entering into the air gap  1   c  pass through the plurality of radial channels  1   d  distributed at intervals along the axial direction of the stator to realize the cooling of the stator winding  1   a  and the stator yoke, the temperature of the cooling air passing through the radial ventilation channels  1   d  rises, the high-temperature cooling air enters the cooling device  10  again through the confluence chamber  25  and the ventilation pipe  23  under the action of the circulation fan  12 , and a next cooling cycle of the airflow organization performs under the action of the circulation fan  12 . 
     In addition, the liquid supply pipe  14  and the liquid/air return pipe  15  of the heat exchanger  11  are located outside the housing  13  of the cooling device  10 , which further simplifies the internal structure of the motor, thereby causing the motor to have a simpler and more compact overall structure and to occupy a smaller space. 
     By providing the confluence chamber  25  and at least one cooling device  10  in communication with the confluence chamber  25  along the circumferential direction of the stator support  20 , the motor provided by the embodiments of the present application can cool the heating components inside the motor in circulation, and has simple and compact overall structure and occupies a small space. 
     The specific structure of the cooling device  10  will be described in further detail below with reference to the accompanying drawings. 
     With reference to  FIG. 3  again, in some embodiments, the circulation fans  12  of two or more cooling devices  10  are provided along the axial direction of the motor to guide the airflow from the heat exchanger  11  to one of the ventilation chambers  31  and to guide the airflow to the other ventilation chamber  31  through the ventilation hole a. Through the organic combination of the cooling device  10  and the stator support  20 , the volume of the circulation fan  12  can be reduced, and compared with a case, in which an integrated circulation fan provided along the axial direction of the stator support  20 , the same heat dissipation effect can be achieved, and also the motor has simple and compact overall structure and occupies a small space. 
     Further, optionally, the two or more cooling devices  10  are uniformly distributed along the circumferential direction of the stator support  20 . Since the ventilation chambers  31  at the two axial ends of the motor have a volume large enough, they can play a role of a static pressure cavity, so the end of the stator winding  1   a  has a uniform cooling effect and also the uniformity of the airflow entering the air gap  1   c  along the axial direction is ensured, the cooling air entering the air gap  1   c  flows along the air gap  1   c  and also through the stator winding  1   a  and the radial ventilation channel  1   d  of the stator core  1   b  into the confluence chamber  25 , and the confluence chamber  25  also has a volume large enough and can play a role of a static pressure cavity, thereby ensuring the uniformity of the airflow in the entire circumferential space, avoiding non-uniform airflow organization, and improving the heat dissipation uniformity of the cooling system. 
     With reference to  FIG. 6  again, the stator support  10  includes a first end plate  26  and a second end plate  27 , which extends along the radial direction and is provided opposite to each other along the axial direction, and an annular plate, which is provided between the first end plate  26  and the second end plate  27 , and the first end plate  26 , the second end plate  27 , and the annular plate  21  form a confluence chamber  201 . 
     Further, the stator support  10  further includes a separation plate  22 , which is connected to the annular plate  21  and extends inwardly along the radial direction, at least one ventilation pipe  23  is further provided between the annular plate  21  and the separation plate  22 , and the cooling device  10  is provided on the separation plate  22  and in communication with the ventilation pipe  23  through the air inlet  1301 . 
     Optionally, the ventilation pipe  23  has an inner wall and an outer wall provided for thermally insulating, so that the cooling air inside the ventilation pipe  23  does not exchange heat with the airflow outside of the ventilation pipe  23  before reaching the housing  13  of the cooling device  10 , and a cavity for effectively sealing the airflow organization is formed among the annular plate  21 , the stator support  20 , the cooling device  10 , and the main shaft  1 , thereby preventing the cooling air entering the housing  13  through the ventilation pipe  23  from being short-circuited during the heat exchange with the heat exchanger  11 . 
     Further, at least one ventilation hole a is provided on the separation plate  22 , the two or more cooling devices  10  are provided on the separation plate  22  at intervals along the circumferential direction of the stator support  20 , and an isolation chamber is formed between every two adjacent cooling devices  10  (not shown in the figure) and in communication with the ventilation hole a. That is, on the radial inner side of the annular plate  21 , the isolation chambers and the housings  13  are alternately disposed along the circumferential direction of the stator support  10 . 
     Since the confluence chamber  25  is in communication with the airflow organization of the heat exchanger  11  in each cooling device  10  through at least one ventilation pipe  23 , and each isolation chamber is in communication with the ventilation chambers  31  at the two axial ends of the motor through the ventilation hole a provided on the separation plate  22 , so after any one of the circulation fans  12  fails, the other circulation fans  12  can still allow the airflow, which is present at the heat exchanger  11  corresponding to the failed circulation fan  12 , to pass through, the heat dissipation requirements of the stator winding  1   a , the stator core  1   b , and the magnetic steel  3   a  corresponding to the failed circulation fan  12  can be taken into account, and the reliability and fault tolerance of the motor are improved. 
     In addition, for working conditions with heavy wind and sand or harsh working environment, in order to avoid insufficient heat dissipation or damage and failure of the components of the motor due to dust accumulation, optionally, a filter  24  is provided at the ventilation hole a of the separation plate  22 . 
     Thus, in one aspect, the housing  13  of the cooling device  10  can be used as a reinforcing rib of the stator support  20 , thereby improving the structural strength and rigidity of the stator support  20 ; in the second aspect, the cooling device  10  is provided on a side of the separation plate  22  as a modular structure and in communication with the external environment, and can be removed directly when the cooling device  10  needs to be replaced or repaired; and if only the heat exchanger  11  needs to be replaced, the cooling device  10  do not have to be removed and only the cover plate  16  on the cooling device  10  needs to be removed, thereby the heat exchanger  11  can be quickly replaced at the inspection opening  136  without removing other components, thereby improving the maintainability of the motor. 
     It should be noted that although for easy of description, the description is made by taking the motor of a structure having the outer rotor and the inner stator structure as an example, it should be understood that, according to the exemplary embodiments of the present application, the working principle of the cooling device  10  described above is also applicable to the motor of a structure having the outer stator and the inner rotor, and the corresponding stator support  20  and rotor support  30  can be modified adaptively. 
     In addition, an embodiment of the present application also provides a wind turbine set, which includes a nacelle and a motor as described above, and the circulation fan  12  of the cooling device  10  of the motor is provided on a side of the nacelle, which is convenient for later installation, maintenance, and replacement. 
     The wind turbine set provided by the embodiments of the present application adopt the motor described above, which can effectively reduce the size of the nacelle, thereby further reducing the whole machine cost and load and improving the reliability and maintainability of the wind turbine set. 
     Moreover, the motor according to the exemplary embodiments described above can be applied to various apparatus that needs to be provided with a motor, for example, but not limited to, a wind turbine set. 
     Those skilled in the art should understand that the embodiments described above are all illustrative and unrestrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Those skilled in the art should be able to understand and realize other modified embodiments of the disclosed embodiments on the basis of studying the drawings, the description, and the claims. In the claims, the term “include” does not exclude other device or step; when an article is not modified by a quantitative word, it is intended to include one/one kind of or more/more kinds of articles, and can be used interchangeably with “one/one kind of or more/more kinds of articles”; and the terms “first” and “second” are used to indicate names rather than to indicate any specific order. Any reference number in the claims should not be understood as limiting the scope of protection. The functions of multiple parts appearing in the claims can be realized by a single hardware or software module. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.