TW559639B - Detached turbulator configuration for cooling passages of gas turbine blades - Google Patents

Abstract

A detached turbulator, which comprises a main body that forms a gap with a primary heat transfer surface, is arranged in a cooling passage to generate wall surface jets that accelerates the fluid and also break down thermal boundary layer and enhance turbulence to increase heat transfer gain and eliminate circulation occurring behind attached turbulator and the accompanying hot spots.

Description

559639 V. Description of the invention (1) ^ [Detailed description of the present invention] The present invention relates to a heat transfer lifting device, especially for the design of the protrusions (ribs) on the surface of the inner cooling channel in the turbine blade, so in fact It is a very practical and progressive invention, which is worthy of being promoted by the industry and being made public. [Background of the invention]

In the field of gas turbines, most people often increase the temperature of the turbine inlet, which can effectively reduce the specific thrust fuel consumption rate, increase the specific power of the turbine, and improve cycle efficiency. Therefore, the design of the advanced turbine has an inlet temperature of 1 700-2000K. However, due to the temperature limit of the turbine blade material, a variety of cooling technologies have been developed for the cooling of turbine blades to reduce the temperature of the blades. Make it reach the range that the material can bear, and the internal cooling channel is one of the widely used cooling technologies. The method is to add the internal channel in the turbine blade and introduce the high-pressure cold air generated by the compressor. The root of the turbine blade enters the blade along the inner flow channel, and the high heat on the blade surface is taken away from the inside of the blade.

The above-mentioned operating structure will be described in detail. Please refer to the first and second figures, which are schematic diagrams of the longitudinal section and cross-section of a gas turbine blade, in which the turbine blade 2000 has serpentine cooling Flow channel 2 1 0, this serpentine cooling flow channel 2 1 0 is composed of multiple radial outflow pipes 2 5 0 (the fluid flows toward the blade top 2 0 1) and radial inflow pipes 2 5 1 (the fluid is away from the blade top 2 0 1 flow), while the radial outflow pipe 250 and the radial inflow pipe 25 1 are composed of the windward wall 30 and the leeward wall

Page 4 559639 V. Description of the invention (2) 3 1 and the inner flow channel formed by the two partition plates 3 2 and 3 3; the cold fluid 2 0 4 enters the serpentine cooling flow channel 2 from the turbine blade root 2 0 2 1 0, flowing through the radial outflow pipe 2 50 and the radial inflow pipe 2 5 1, and finally can be discharged through the hole 2 0 3 on the blade top 2 0 1; as mentioned above, but generally the artificial cooling is increased. The heat transfer efficiency of the flow channel is a common practice. Ribs or turbulence gainers with different shapes and configurations are arranged on the surface of the internal cooling flow channel. The main purpose is to increase the flow through the more intense interaction between the fluid and the wall. Heat transfer. However, for the conventional rib structure, please refer to the third figure, which is a side view of the cooling method of the inner channel with a conventional orthogonal rib in a radial outflow and a cross-sectional view of A—A. Main heat transfer wall surface: The inner surface of the windward wall 3A and the inner surface of the leeward wall 3 1A are added with close-fitting orthogonal ribs 40. The flow field around the ribs is accelerated by 1 1 to destroy the growth of the thermal boundary layer and increase the turbulence. Flow energy to improve heat transfer efficiency, or as shown in the fourth figure, it is a side view and a B-B cross-sectional view of the cooling method of a conventional internally-adhered orthogonal rib in a radial inflow. The inner surface of the windward wall 3 Ο A and the inner surface of the leeward wall 3 1 A are added with orthogonal ribs to promote heat transfer efficiency. However, the above two structures have not been perfected in use. The defects are described as follows: 1. First, a low-speed recirculation zone 12 will be generated at the trailing edge of the rib 40 in the third or fourth picture, which will cause local low heat transfer areas, and there will be hot spots, which affect the effectiveness of the overall structure; 2. Also, when the turbine is running (rotation direction 100), the blade The flow passage 250 and the fluid will affect the inner blade 251 is rotated by the

Page 5 559639 V. Description of the invention (3) When subjected to a rotating force, this rotating force is known as the Coriolis force, and the Coriolis force will cause the fluid in the inner channel to circulate, as shown in the third figure, The direction of this circulating flow is related to the direction of the radial flow of the fluid in the internal flow channel. The third diagram depicts a pair of opposite circulating flows formed in the radially outward flowing pipeline 2 5 0 due to the Coriolis force. 16 to move the fluid from the windward wall 30 to the leeward wall 31. In contrast, the fourth diagram depicts the reverse circulating flow 17 and 18 formed by the Coriolis force in the radial inflow pipe 2 5 1, so that the fluid moves from the leeward wall 31 to the windward wall 30; Due to the influence of the Coriolis force, the fluid 10 in the inner flow channel is directed toward the leeward wall 3 1, and secondary flows 15 and 16 are formed. The secondary flows 15 and 16 directly impact the inner surface 3 of the leeward wall. 1 A, thus increasing the heat transfer gain of the leeward wall 31, and as shown in the fourth figure, the Coriolis force is directed toward the windward wall 30 due to the different flow direction of the mainstream 20, and the secondary flow 1 7 and 1 8 formed directly Shock the inner surface of the windward wall 30A, increase the heat transfer benefit of the windward wall 30. As can be seen from the above, although the secondary flow 15 and 16 can increase the heat transfer benefit on one side, it will cause the heat transfer effect to deteriorate on the other side. As shown in the third and fourth figures, when the tube flow is radially outward, the leeward wall heat transfer gain is deteriorated, and the windward wall heat transfer becomes worse, and when the tube flow is radially inward, the leeward wall heat is increased. The heat transfer will be worse, and the heat transfer of the windward wall will show a gain. From this, it can be known that the conventional turbulence gain device is not only easy to rib 40 The low-speed recirculation zone 12 is generated, resulting in hot spots in the local low heat transfer area. It will also be caused by the Coriolis force when the blades rotate, which is mainly due to the previous technology. design

Page 6 559639 559639 V. Description of the invention (5) · The present invention relates to a non-adherent turbulence gain device for a cooling channel in a turbine blade. Please refer to the fifth and sixth figures of the present invention. Side view and cross-sectional view of a wall-mounted turbulence gainer and its configuration in the inner channel cooling mode of radial outward and radial inflow. As shown in the fifth and sixth figures, the rib 41 and the main heat transfer wall surface: There is a gap C between the windward wall 30 and the leeward wall 31, and when the fluid flows through this gap C, a wall jet 13 and a The fluid has an acceleration effect, which can increase the turbulent flow energy, increase the heat transfer gain, and eliminate hot spots generated by the adherent ribs. According to the actual experimental results (as shown in Table 1, please refer to Annex 1), the non-adherent turbulence gainer 41 is located on the windward wall 30 of the radial outflow 2 50 and the leeward wall of the radial inflow. 3 1, which has a better heat transfer coefficient than the conventional wall-mounted orthogonal ribs 40, which can increase by about 21%, but the non-wall-mounted turbulence gainer 41 is leeward from the radial outflow 2 5 0 The wall 31 and the windward wall 30 of the radial inward flow have a lower heat transfer coefficient than the conventional wall-mounted orthogonal ribs 40, which is due to the wall surface generated by the non-wall-mounted turbulence gain device 41. The jets 1 3 weaken the impact of the fluid on the wall due to the Coriolis force. In addition, as shown in Table 2, the heat transfer uniformity of the non-adherent turbulence gainer 41 is better than that of the conventional orthogonal ribs 40. Based on the above, it is true that the inventor has invented a non-adherent / adherent turbulence gain device and a configuration manner thereof. The seventh and eighth figures are side and cross-sectional views of a non-adherent / adherent turbulent flow gain device and a cooling method of an inner flow channel in a radial outflow and a radial inflow according to the present invention. As seventh

Page 8 559639 V. Description of the invention (6) As shown in the figure and the eighth figure, the rib 4 1 and the inner surface of the windward wall 3 0 A with radial outflow 2 5 0 and the inner surface of the leeward wall 3 1 B with radial inflow exist. Gap C, when the fluid flows through this gap C, the wall jet 13 and the acceleration of the fluid can increase the abandoned flow energy, improve the heat transfer coefficient, and eliminate the hot spots generated by point wall ribs; ribs 4 0 It is tightly connected to the inner surface 3 1 A of the leeward wall with radial outflow 2 50 and the inner surface 3 0 B of the windward wall with radial inflow to maintain the Coriolis force and maintain a better heat transfer coefficient. The ninth figure and the tenth figure are schematic diagrams of design parameters of the non-adherent / adherent turbulence gain device and its configuration of the present invention. The width of the wall or wall-mounted rib, B represents the length of the non-wall-mounted or wall-mounted rib, and C represents the gap between the non-wall-mounted rib and the main heat transfer wall surface, where the value of W / H is between 0 · Any value between 2 and 5 and the value of C / Η is any value between 0 · 2 — 1. P represents the rib pitch, that is, the distance between adjacent heat transfer gain devices. The non-adherent / adherent turbulence gain devices 41 and 40 of the present invention can arbitrarily select the rib pitch P according to the length of the inner flow channel. The wall surface of the inner flow channel is arranged in various quantities to achieve the purpose of cooling the inner flow channel. The first table is a comparison of the heat transfer gain performance of the present invention and the conventional adherent orthogonal ribs in the cooling design of the inner flow channel. The results show that the non-adherent turbulence gainer 41 is in the windward wall of the radial outflow 2 50. The leeward wall 3 1 of 3 0 and radial inflow 2 5 1 has a better heat transfer coefficient than the conventional close-mounted orthogonal ribs 40, which can increase up to about 21%. However, non-adherent turbulence Gainer 4 1 leeward wall 3 1 with radial outflow 2 5 0 and windward wall 3 0 with radial inward flow 2 5 1 have worse performance than the conventional close-mounted orthogonal rib 4 0

Page 9 559639 V. May explanation (The heat transfer gain of Ό. And the non-adherent / adherent turbulence gain device of the present invention flows outward in the radial wall 2 50 and the radial inflow 2 50 The leeward wall 3 1 of 2 5 1 has a better heat transfer gain than the conventional close-mounted orthogonal ribs 40, which can increase up to about 4 2%, while the leeward wall 3 1 and the radial outflow 2 5 0 The windward wall 3 0 flowing inward 2 5 1 can still maintain the heat transfer gain of the close orthogonal ribs 40.

The second table is a comparison of the heat transfer inhomogeneity between the present invention and the conventional orthogonal ribs in the inner channel cooling design. The results show that the non-adherent turbulence gainer 41 has the best thermal uniformity. Non-adherent / adherent turbulence gainers are next, and adhering orthogonal ribs 40 are the worst. Explanation of Annex 1: Table 1: The experimental results of comparison of the heat transfer coefficients of the present invention and the conventional technology (adhered orthogonal ribs). Table 2: The experimental results of the heat transfer inhomogeneity comparison between the present invention and the conventional technique (adherent orthogonal ribs).

Page ί 559639 Brief description of the drawings / The preferred embodiment of the present invention can be described in more detail in conjunction with the attached drawings, so that the reviewers can obtain a further understanding of the present invention, of which: A · Main Description of component symbols: 10 The main stream of cooling fluid flowing radially 11 The fluid around the ribs 12 Low-speed return zone 13 Wall spray 15 The second stream 16 The second stream 17 The second stream 18 The second stream 20 The main stream of cooling fluid radially inward 21 Fluid around the ribs 23 Wall jet 30 Windward wall 3 0 A Inward wall of radial outflow 3 0 B Inward wall of radial inflow 31 Leeward wall 3 1 A Outward wall of radial outflow 3 1 B Inward radial Inside surface of the leeward wall of the stream 32 Left partition 33 Right partition 40 Adhesive orthogonal ribs

Page 11 559639 Λ Month Amendment No. 91110475 Brief description of the diagram 50 Air inlet 51 Mesh heater 52 Argon ion laser 53 Motor 54 Blower 55 Exhaust 56 Computer B Schematic diagram of the longitudinal section of a turbine blade. The second diagram is a schematic diagram of the cross section of a gas turbine blade. • The second diagram is the cooling method of the close-out orthogonal ribs in the radial outflow pipe. The fourth diagram is the close-up orthogonal ribs in the radial direction. The cooling method of internal flow pipes, the fifth figure is the cooling method of the non-adherent orthogonal ribs of the present invention in the radial outflow pipe. The seventh diagram is the cooling method of the non-adherent / adherent orthogonal ribs in the radial outflow pipe according to the present invention. The eighth diagram: The non-adhesive according to the present invention Cooling method of wall / adherent orthogonal ribs in radial inflow pipes, Figure 9: Schematic diagram of design parameters of non-adherent / adherent orthogonal ribs in radial outflow pipes of the present invention, Tenth TS1 diagram : It is a schematic diagram of the design parameters of the non-adherent / adherent orthogonal ribs in the radial inflow pipeline of the present invention; and the eleventh diagram: a schematic diagram of the equipment of the experiment.

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Claims (1)

559639 VI. Application for patent enclosing sacrifice · '1. A non-adherent turbulence gain device, the main body of which is a rib with any cross section, with a gap between the rib and the wall. 2. The non-adherent turbulence gain device as described in item 1 of the scope of patent application, wherein the ribs are rectangular. 3. The turbulence gain device as described in the second item of the patent application, wherein the width-to-height ratio of the rectangular cross-section ribs can be any selected value greater than 0 · 2 and less than 5. The turbulence gain as described in the first item of the patent application Device, wherein the ratio of the gap to the rib height can be any selected value greater than 0 · 2 and less than 1. 5. If the turbulence gain device in the first item of the patent application scope, the main body is a rib with a triangular cross section. 6. The turbulence gain device according to item 5 of the patent application, wherein the rib cross section can be any triangle. 7. The turbulence gain device according to item 5 of the patent application, wherein the ratio of the gap to the rib height can be any selected value greater than 0 · 2 and less than 1. 8. As for the turbulence gain device in the first scope of the patent application, the main body is a circular cross-section rib. 9. The turbulence booster according to item 8 of the scope of the patent application, wherein the ratio of the gap to the diameter of the circular cross-section rib may be any selected value greater than 0 · 2 and less than 1. 10. An internal flow channel cooling method adopts the turbulence gain device of the first patent application scope. The turbulence gain device can be combined in any number and position and placed on the wall surface of the internal flow channel. 1 1. A non-adherent / adherent turbulence gain configuration, using Page 14 559639 VI. Application for patent scope The non-adherent turbulence booster of item 1 of the patent scope is placed on the wall surface of the inner flow channel opposite to the Coriolis force direction. The inner flow channel wall surface with the same force direction to improve the heat transfer efficiency. Page 15