Patent Publication Number: US-2015063991-A1

Title: Turbine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of International Patent Application No. PCT/CN2012/000714 with an international filing date of May 22, 2012, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201210137082.5 filed May 7, 2012. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. Inquiries from the public to applicants or assignees concerning this document or the related applications should be directed to: Matthias Scholl P.C., Attn.: Dr. Matthias Scholl Esq., 245 First Street, 18th Floor, Cambridge, Mass. 02142. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to the field of turbocharging of an internal combustion engine, and more particularly to a turbine. 
     2. Description of the Related Art 
     A typical double-layer flow passage cross-section variable turbocharger, as shown in  FIG. 1 , includes a turbine. The turbine includes a volute  1  and an impeller  2 . The volute  1  includes: a volute gas inlet  3 , a volute gas feeding flow passage, and a volute gas outlet  4 . A middle partition  5  is circumferentially disposed inside the volute gas feeding flow passage. The middle partition  5  divides the volute gas feeding flow passage into a left flow passage  6  and a right flow passage  7 . The impeller  2  includes: an impeller gas inlet  8 , an impeller gas feeding flow passage  9 , and an impeller gas outlet  10 . A valve control mechanism is disposed at the left flow passage  6  or at the right flow passage  7  in the vicinity of the volute gas inlet  3  for realizing single flow passage working or double-flow passage co-working, thereby changing the flow area of the volute flow passage. 
     However, in practical applications, when the motor operates at low speeds, the efficiency of the turbine is relatively low because only a single flow passage of the volute is utilized and the exhaust gas discharged from the motor enters the volute gas inlet and passes through the single flow passage to reach the gas outlet of the single flow passage where sudden expansion of the gas easily occurs, so that the gas entering the impeller gas feeding flow passage from the impeller gas inlet is reduced. Also, when the motor operates at middle or high speeds, the efficiency of the turbine is relatively low because while both of the flow passages of the volute are utilized, the exhaust gas discharged from the motor enters the volute gas inlet and passes through the double flow passages to reach the impeller gas inlet where the gas of the two flow passages is mixed, so that a part of the kinetic energy of the gas entering the impeller gas feeding flow passage is converted into the potential energy. 
     SUMMARY OF THE INVENTION 
     In view of the above-described problems, it is one objective of the invention to provide a double-area turbine for turbocharging, the turbine being capable of reducing the sudden expansion phenomenon of the gas at the gas outlet of the single flow passage of the volute in conditions of small flow rate as well as reducing the mixing phenomenon of the gas from the two flow passages of the volute at the impeller gas inlet, therefore improving the efficiency of the double-layer flow passage cross-section variable turbocharger in the full range of working conditions of the motor. 
     To achieve the above objective, in accordance with one embodiment of the invention, there is provided a turbine, comprising: a volute and an impeller. The volute comprises: a volute gas inlet, a volute gas feeding flow passage, and a volute gas outlet. The impeller comprises: blades, an impeller gas feeding flow passage, an impeller gas inlet, an impeller gas outlet, and a partition plate. The impeller gas feeding flow passage comprises an inner flow passage and an outer flow passage. The impeller is disposed inside the volute. The blades are disposed on an outer part of the impeller. The partition plate is circumferentially disposed between the impeller gas inlet and the impeller gas outlet. The partition plate divides the impeller gas feeding flow passage into the inner flow passage and the outer flow passage. 
     In a class of this embodiment, the volute gas feeding flow passage comprises a middle partition, and the middle partition divides the volute gas feeding flow passage into a left flow passage and a right flow passage. The left flow passage communicates with the inner flow passage. The right flow passage communicates with the outer flow passage. 
     In a class of this embodiment, the left flow passage comprises a gas outlet of the left flow passage in the vicinity of the impeller. The right flow passage comprises a gas outlet of the right flow passage in the vicinity of the impeller. The inner flow passage comprises a gas inlet of the inner flow passage corresponding to the gas outlet of the left flow passage. The outer flow passage comprises a gas inlet of the outer flow passage corresponding to the gas outlet  8  of the right flow passage. 
     In a class of this embodiment, a ratio of a width of the gas inlet of the inner flow passage to a width of the gas inlet of the outer flow passage is between 0.1 and 10. 
     In a class of this embodiment, the inner flow passage is a radial inflow channel. 
     In a class of this embodiment, the inner flow passage is a Francis channel. 
     In a class of this embodiment, the outer flow passage is a radial inflow channel. 
     In a class of this embodiment, the outer flow passage is a Francis channel. 
     In a class of this embodiment, a ratio of a width of the gas outlet of the inner flow passage to a width of the gas outlet of the outer flow passage is between 0.1 and 10. 
     In a class of this embodiment, the blade comprises inner blades correspondingly disposed inside the inner flow passage and outer blades correspondingly disposed inside the outer flow passage. 
     In a class of this embodiment, a ratio of a number of the inner blades to a number of the outer blades is between 0.2 and 6. 
     In a class of this embodiment, an adjustable valve is disposed inside the left flow passage in the vicinity of the volute gas inlet. The adjustable valve is connected to a control mechanism. 
     Both the right flow passage and the outer flow passage are normal open passages. 
     When a motor operates at a low rotational speed working condition, a relatively small amount of exhaust gas is discharged from the motor, and the adjustable valve is in a close state driven by the control mechanism. Since either a first flow path including the left flow passage, the gas inlet of the inner flow passage, and the inner flow passage or a second flow path including the right flow passage, the gas inlet of the outer flow passage, and the outer flow passage is opened, the left flow passage, the gas inlet of the inner flow passage, and the inner flow passage are also in the close sate. The exhaust gas discharged from the motor only passes through the right flow passage, the gas inlet of the outer flow passage, and the outer flow passage to do work, so that a sudden expansion phenomenon of the gas at the outlet of the left flow passage is reduced, the intake pressure of the outer flow passage is effectively increased, and the exhaust energy entering the turbine is increased. With the increase of the intake energy of the turbine, the energy in the exhaust gas is fully utilized, and therefore the efficiency of the turbine and the torque output are improved. 
     When the motor operates at a high rotational speed working condition, a relatively large amount of the exhaust gas is discharged from the motor, and the adjustable valve is in an open state driven by the control mechanism. Because the left flow passage, the gas inlet of the inner flow passage, and the inner flow passage communicate with each other, and because the right flow passage, the gas inlet of the outer flow passage, and the outer flow passage communicate with each other, the exhaust gas discharged from the motor separately passes through a first flow path comprising the left flow passage, the gas inlet of the inner flow passage, and the inner flow passage and through a second flow path comprising the right flow passage, the gas inlet of the outer flow passage, and the outer flow passage to do work. Thus, the mixing phenomenon of the gas from the left flow passage and the gas from the right flow passage at the impeller gas inlet is reduced. The opening degree of the adjustable valve is controlled by the control mechanism so as to reasonably allocate the gas flows entering the two flow paths of the turbine. Since the two flow paths of the turbine are different in flow capacity, the exhaust pressure of the motor and the power output of the turbine can be effectively regulated by changing the intake flow ratio between the two flow paths of the turbine, thereby satisfying the performance and the emission requirement of the middle and high rotational speed working condition of the motor. 
     In a class of this embodiment, an adjustable valve is disposed inside the right flow passage in the vicinity of the volute gas inlet. The adjustable valve is connected to a control mechanism. 
     Both the left flow passage and the inner flow passage are both normal open passages. 
     When the motor operates at the low rotational speed working condition, a relatively small amount of exhaust gas is discharged from the motor, and the adjustable valve is in the close state driven by the control mechanism. Since either a first flow path including the left flow passage, the gas inlet of the inner flow passage, and the inner flow passage or a second flow path including the right flow passage, the gas inlet of the outer flow passage, and the outer flow passage is opened, the right flow passage, the gas inlet of the outer flow passage, and the outer flow passage are also in the close sate. The exhaust gas discharged from the motor only passes through the left flow passage, the gas inlet of the inner flow passage, and the inner flow passage to do work, so that a sudden expansion phenomenon of the gas at the outlet of the right flow passage is reduced, the intake pressure of the inner flow passage is effectively increased, and the exhaust energy entering the turbine is increased. With the increase of the intake energy of the turbine, the energy in the exhaust gas is fully utilized, and therefore the efficiency of the turbine and the torque output are improved. 
     When the motor operates at a high rotational speed working condition, a relatively large amount of the exhaust gas is discharged from the motor, and the adjustable valve is in an open state driven by the control mechanism. Because the left flow passage, the gas inlet of the inner flow passage, and the inner flow passage communicate with each other, and because the right flow passage, the gas inlet of the outer flow passage, and the outer flow passage communicate with each other, the exhaust gas discharged from the motor separately passes through a first flow path comprising the left flow passage, the gas inlet of the inner flow passage, and the inner flow passage and through a second flow path comprising the right flow passage, the gas inlet of the outer flow passage, and the outer flow passage to do work. Thus, the mixing phenomenon of the gas from the left flow passage and the gas from the right flow passage at the impeller gas inlet is reduced. The opening degree of the adjustable valve is controlled by the control mechanism so as to reasonably allocate the gas flows entering the two flow paths of the turbine. Since the two flow paths of the turbine are different in flow capacity, the exhaust pressure of the motor and the power output of the turbine can be effectively regulated by changing the intake flow ratio between the two flow paths of the turbine, thereby satisfying the performance and the emission requirement of the middle and high rotational speed working condition of the motor. 
     Advantages according to embodiments of the invention are summarized as follows: 
     The turbine volute of the invention has simple structure, excellent succession, and relatively high casting yield. The turbine impeller of the invention acquires high aerodynamic efficiency and high structural strength by analysis and optimization of the modern Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) technology. The impeller can be produced by adopting the existing casting and processing devices, which has low production cost and easily realizes engineering. In summary, the double-area turbine is capable of effectively satisfying the turbocharging requirement in a full range of working condition of the motor, that is, in conditions of small flow rate, the sudden expansion phenomenon of the gas at the gas outlet of the single flow passage of the volute is decreased, and the efficiency of the turbine in conditions of the small flow rate is further improved; in conditions of normal flow rate, the mixing phenomenon of the gas from the two flow passages of the volute at the impeller gas inlet is decreased so as to improve the efficiency of the turbine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described hereinbelow with reference to the accompanying drawings, in which: 
         FIG. 1  is a structure diagram of a double-layer flow passage cross-section variable turbocharger in the prior art; 
         FIG. 2  is a structure diagram of a double-area turbine in accordance with Example 1 and Example 2; 
         FIG. 3  is a structure diagram of an impeller in accordance with Example 1 and Example 2; 
         FIG. 4  is a right view of  FIG. 3 ; 
         FIG. 5  is a structure diagram of an adjustable valve mounted inside a left flow passage in accordance with Example 1; and 
         FIG. 6  is a structure diagram of an adjustable valve mounted inside a right flow passage in accordance with Example 2. 
     
    
    
     In the drawings, the following reference numbers are used:  1 . Volute;  2 . Turbine impeller;  3 . Volute gas inlet;  4 . Volute gas outlet;  5 . Middle partition;  6 . Left flow passage;  7 . Right flow passage;  8 . Impeller gas inlet;  9 . Impeller gas feeding flow passage;  10 . Impeller gas outlet;  11 . Partition plate;  12 . Inner flow passage;  13 . Outer flow passage;  14 . Impeller inner blade;  15 . Impeller outer blade;  16 . Gas outlet of left flow passage;  17 . Gas inlet of inner flow passage;  18 . Gas outlet of right flow passage;  19 . Gas inlet of outer flow passage;  20 . Adjustable valve; W1. Width of gas inlet of inner flow passage; W2. Width of gas inlet of outer flow passage; W3. Width of gas outlet of inner flow passage; and W4. Width of gas outlet of outer flow passage. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     For further illustrating the invention, examples detailing a double-area turbine for turbocharging are described below. It should be noted that the following examples are intended to describe and not to limit the invention. 
     Example 1 
     As shown in  FIGS. 2-3 , a double-area turbine for turbocharging comprises a volute  1  and an impeller  2  disposed inside the volute  1 . Blades are disposed at an outer part of the impeller  2 . The volute  1  comprises: a volute gas inlet  3 , a volute gas feeding flow passage, and a volute gas outlet  4 . 
     The impeller  2  comprises: an impeller gas inlet, an impeller gas feeding flow passage, an impeller gas outlet, and blades. 
     A partition plate  11  is circumferentially disposed between the impeller gas inlet and the impeller gas outlet. The shape of the partition plate  11  satisfies aerodynamic performance requirements and reliability requirements. 
     The partition plate  11  divides the impeller gas feeding flow passage into an inner flow passage  12  and an outer flow passage  13 . 
     The inner flow passage  12  adopts a radial inflow channel or Francis channel. The outer flow passage  13  is generally designed to be a radial inflow channel and is designed to be a Francis channel in special circumstances. 
     A ratio of a width W1 of the gas inlet of the inner flow passage to a width W2 of the gas inlet of the outer flow passage is between 0.1 and 10. 
     A ratio of a width W3 of the gas outlet of the inner flow passage to a width W4 of the gas outlet of the outer flow passage is between 0.1 and 10. 
     The volute gas feeding flow passage comprises a middle partition  5 . The middle partition  5  divides the volute gas feeding flow passage into a left flow passage  6  and a right flow passage  7 . 
     The left flow passage  6  communicates with the inner flow passage  12 . The right flow passage  7  communicates with the outer flow passage  13 . 
     A gas outlet of the left flow passage  6  is corresponding to a gas inlet  17  of the inner flow passage  12 . A gas outlet  18  of the right flow passage  7  is corresponding to a gas inlet  19  of the outer flow passage  13 . 
     As shown in  FIG. 4 , the blades comprise inner blades  14  correspondingly disposed inside the inner flow passage  12  and outer blades  15  correspondingly disposed inside the outer flow passage  13 . A ratio of a number of the inner blades  14  to a number of the outer blades  15  is between 0.2 and 6. 
     As shown in  FIG. 5 , an adjustable valve  20  is disposed inside the left flow passage  6  in the vicinity of the volute gas inlet  3 . The adjustable valve  20  is connected to a control mechanism. Driven by the control mechanism, the rotation of the adjustable valve  20  is realized, so that the left flow passage  6  is opened or closed. 
     When a motor operates at a low rotational speed working condition, a relatively small amount of exhaust gas is discharged from the motor, and the adjustable valve  20  is in a close state driven by the control mechanism. Thus, the left flow passage  6 , the gas inlet  17  of the inner flow passage, and the inner flow passage  12  are also in the close sate. The exhaust gas discharged from the motor only passes through the right flow passage  7 , the gas inlet  19  of the outer flow passage, and the outer flow passage  13  to do work, so that a sudden expansion phenomenon of the gas at the outlet  16  of the left flow passage is reduced, the intake pressure of the outer flow passage  13  is effectively increased, and the exhaust energy entering the turbine is increased. With the increase of the intake energy of the turbine, the energy in the exhaust gas is fully utilized, and therefore the efficiency of the turbine and the torque output are improved. 
     When the motor operates at a high rotational speed working condition, a relatively large amount of the exhaust gas is discharged from the motor, and the adjustable valve  20  is in an open state driven by the control mechanism. Because the left flow passage  6 , the gas inlet  17  of the inner flow passage, and the inner flow passage  12  communicate with each other, and because the right flow passage  7 , the gas inlet  19  of the outer flow passage, and the outer flow passage  13  communicate with each other, the exhaust gas discharged from the motor separately passes through a first flow path comprising the left flow passage  6 , the gas inlet  17  of the inner flow passage, and the inner flow passage  12  and through a second flow path comprising the right flow passage  7 , the gas inlet  19  of the outer flow passage, and the outer flow passage  13  to do work. Thus, a mixing phenomenon of the gas from the left flow passage  6  and the gas from the right flow passage  7  at the impeller gas inlet is reduced. The opening degree of the adjustable valve  20  is controlled by the control mechanism so as to reasonably allocate the gas flows entering the two flow paths of the turbine. Since the two flow paths of the turbine are different in flow capacity, the exhaust pressure of the motor and the power output of the turbine can be effectively regulated by changing the intake flow ratio between the two flow paths of the turbine, thereby satisfying the performance and the emission requirement of the middle and high rotational speed working condition of the motor. 
     Example 2 
     As shown in  FIG. 6 , the turbine of this example is different from that in Example  1  in that the adjustable valve  20  herein is disposed inside the right flow passage  7  in the vicinity of the volute gas inlet  3  rather than being disposed inside the left flow passage  6  in the vicinity of the volute gas inlet  3  in Example 1. The adjustable valve  20  is connected to a control mechanism. The rotation of the adjustable valve  20  can be realized driven by the control mechanism, so that the right flow passage  7  is opened or closed. 
     When the motor operates at the low rotational speed working condition, a relatively small amount of exhaust gas is discharged from the motor, and the adjustable valve  20  is in a close state driven by the control mechanism. Thus, the right flow passage  7 , the gas inlet  19  of the outer flow passage, and the outer flow passage  13  are also in the close sate. The exhaust gas discharged from the motor only passes through the left flow passage  6 , the gas inlet  17  of the inner flow passage, and the inner flow passage  12  to do work, so that the sudden expansion phenomenon of the gas at the outlet  18  of the right flow passage is reduced, the intake pressure of the inner flow passage  12  is effectively increased, and the exhaust energy entering the turbine is increased. With the increase of the intake energy of the turbine, the energy in the exhaust gas is fully utilized, and therefore the efficiency of the turbine and the torque output are improved. 
     When the motor operates at a high rotational speed working condition, a relatively large amount of the exhaust gas is discharged from the motor, and the adjustable valve  20  is in an open state driven by the control mechanism. Because the left flow passage  6 , the gas inlet  17  of the inner flow passage, and the inner flow passage  12  communicate with each other, and because the right flow passage  7 , the gas inlet  19  of the outer flow passage, and the outer flow passage  13  communicate with each other, the exhaust gas discharged from the motor separately passes through a first flow path comprising the left flow passage  6 , the gas inlet  17  of the inner flow passage, and the inner flow passage  12  and through a second flow path comprising the right flow passage  7 , the gas inlet  19  of the outer flow passage, and the outer flow passage  13  to do work. Thus, the mixing phenomenon of the gas from the left flow passage  6  and the gas from the right flow passage  7  at the impeller gas inlet is reduced. The opening degree of the adjustable valve  20  is controlled by the control mechanism so as to reasonably allocate the gas flows entering the two flow paths of the turbine. Since the two flow paths of the turbine are different in flow capacity, the exhaust pressure of the motor and the power output of the turbine can be effectively regulated by changing the intake flow ratio between the two flow paths of the turbine, thereby satisfying the performance and the emission requirement of the middle and high rotational speed working condition of the motor. 
     While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.