Turbine blade with bionic leaf-shaped regenerative cooling channel

Abstract

The invention discloses a turbine blade with a bionic leaf-shaped regenerative cooling channel, the bionic leaf-shaped regenerative cooling channel comprises an outlet cooling channel, a main leaf vein cooling channel, at least four secondary leaf vein cooling channels, at least two transition cooling channels and a plurality of branch leaf vein cooling channels, and a cooling liquid inlet is used for introducing cooling fluid; and cooling fluid is uniformly conveyed to the outlet cooling channel through the main blade vein cooling channel, the secondary blade vein cooling channel, the branch blade vein cooling channel and the transition cooling channel in sequence and is finally guided out through the two cooling liquid outlets, and cooling of the turbine blade is completed. The problems that when an existing turbine blade adopting a single rotary cooling channel is used for cooling, a blade body is not evenly cooled, and the overall cooling effect is poor are solved.

Description

[Technical field]

[0001] The invention belongs to the technical field of turbine blade cooling channels, and in particular relates to a turbine blade with a bionic leaf-shaped regenerative cooling channel. [Background technology]

[0002] With the development of aviation technology, the performance of turbine-based combined cycle engines, namely TBCC engines, has been continuously improved, and the temperature before the turbine has continued to rise, greatly increasing the thermal load of the turbine blades. In this case, it is particularly important to efficiently cool the high-temperature components of the turbine. In recent years, the improvement in engine performance has been partly attributed to the progress of cooling technology. Common turbine blade cooling methods include internal convection cooling and external film cooling. In the internal convection cooling method, the internal cooling channel mostly uses a single rotary cooling channel, but the rotary cooling channel is limited by the limited heat exchange area and insufficient contact between the cold air and the hot wall, resulting in uneven cooling of the turbine blades, especially uneven cooling of the blade body, and the temperature at the blade tip, the leading edge of the blade and the trailing edge of the blade after cooling has basically not changed. Therefore, the cooling of the turbine blades of the TBCC engine is still a technical problem that needs to be solved urgently. The cooling of the turbine blades has an important impact on improving the performance and reliability of the TBCC engine. [Summary of the invention]

[0003] The purpose of the present invention is to provide a turbine blade with a bionic leaf-shaped regenerative cooling channel to solve the problem of uneven cooling of the blade body and poor overall cooling effect when the existing turbine blades using a single rotary cooling channel are cooled.

[0004] The present invention adopts the following technical scheme: a turbine blade with a bionic leaf-shaped regenerative cooling channel, comprising a turbine blade and a bionic leaf-shaped regenerative cooling channel arranged in the blade, wherein the turbine blade has a blade body; the bottom end and the top end of the blade body are respectively a blade root and a blade tip; the two sides of the blade body are respectively a blade leading edge and a blade trailing edge;

[0005] The bionic leaf-shaped regenerative cooling channel includes:

[0006] An outlet cooling channel is arranged in the blade body, which is a cooling channel that is arranged through the edges of the leading edge, the blade top and the trailing edge of the blade; the two intersections of the outlet cooling channel and the blade root are both coolant outlets;

[0007] A main blade vein cooling channel is vertically arranged at the inner center of the blade body; the intersection of one end of the main blade vein cooling channel and the blade root is the coolant inlet, and the other end is not connected with the outlet cooling channel;

[0008] At least four secondary blade vein cooling channels are symmetrically arranged on the left and right sides of the main blade vein cooling channel and are all inclined toward the blade top; one end of each secondary blade vein cooling channel is connected to the main blade vein cooling channel, and the other end is not connected to the outlet cooling channel;

[0009] At least two transition cooling channels are symmetrically arranged on the left and right sides of the main blade vein cooling channel; each transition cooling channel is located between two adjacent secondary blade vein cooling channels; one end of each transition cooling channel is connected to the outlet cooling channel, and the other end is not connected to the main blade vein cooling channel;

[0010] Multiple branch vein cooling channels, which are channels branched from the upper and lower sides of each secondary vein cooling channel; wherein each branch vein cooling channel below the two secondary vein cooling channels near the blade root extends to both sides and is connected to the outlet cooling channel; each branch vein cooling channel between each secondary vein cooling channel and the adjacent transition cooling channel converges to the transition cooling channel; each branch vein cooling channel above the two secondary vein cooling channels near the blade top is connected to the outlet cooling channel;

[0011] The cross-sectional areas of the main blade vein cooling channel, the secondary blade vein cooling channel, the transition cooling channel and the branch blade vein cooling channel decrease step by step;

[0012] Among them, the coolant inlet is used to introduce the cooling fluid, and the cooling fluid is evenly transported to the outlet cooling channel through the main vein cooling channel, the secondary vein cooling channel, the branch vein cooling channel and the transition cooling channel in sequence, and finally discharged through the two coolant outlets to complete the cooling of the turbine blades.

[0013] Furthermore, the secondary vein cooling channels located on the same side of the primary vein cooling channel are parallel to each other and spaced apart.

[0014] Furthermore, each transition cooling channel is parallel to an adjacent secondary blade vein cooling channel.

[0015] Furthermore, each transition cooling channel is located in the middle between two adjacent secondary blade vein cooling channels.

[0016] Furthermore, each branch vein cooling channel located on the same side of each secondary vein cooling channel is parallel to each other.

[0017] Furthermore, the cross-sectional shapes of the main blade vein cooling channel, the secondary blade vein cooling channel, the transition cooling channel and the branch blade vein cooling channel are the same;

[0018] Among them, when the cross-sectional shape is a rectangle, the long side lengths of the cross-sectional areas of the main vein cooling channel, the secondary vein cooling channel, the transition cooling channel and the branch vein cooling channel are Lmain, Lsecondary, Ltransition and Lbranch respectively, then Lmain>Lsecondary>Ltransition>Lbranch.

[0019] Furthermore, the length of the long side of the cross section of each branch vein cooling channel is equal to the interval width between two adjacent branch vein cooling channels.

[0020] Furthermore, when the cross-sectional shape is a square, assuming that the side lengths of the cross-sectional areas of the main vein cooling channel, the secondary vein cooling channel, the transition cooling channel and the branch vein cooling channel are l main, l secondary, l transition and l branch respectively, then l main > l secondary > l transition > l branch.

[0021] Furthermore, when the cross-sectional shape is circular, the cross-sectional diameters of the main vein cooling channel, the secondary vein cooling channel, the transition cooling channel and the branch vein cooling channel are respectively Rmain, Rsecondary, Rtransition and Rbranch, then Rmain>Rsecondary>Rtransition>Rbranch.

[0022] Furthermore, the cross-sectional dimensions are set to meet the following requirements:

[0023] L transition > 2L branch, L secondary > 2L transition, L main > 2L secondary;

[0024] Or, 1 transition > 21 branches, 1 secondary > 21 transitions, 1 main > 21 secondary;

[0025] Or, Rtransition>2Rbranch, Rsecondary>2Rtransition, Rmain>2Rsecondary.

[0026] The beneficial effects of the present invention are:

[0027] First, the present invention arranges a plurality of cooling channels inside the turbine blade body, and the positions of the cooling channels are arranged in accordance with the direction of the leaf veins. The inlet collecting chamber of the regeneration cooling channel is arranged to be similar to the main vein of the leaf, that is, the main vein cooling channel, and the arrangement of the remaining cooling channels is arranged in accordance with the secondary veins and branch veins of the leaf, that is, the secondary vein cooling channel and the branch vein cooling channel. The size of each cooling channel is arranged according to the required pressure difference. The cooling fluid in the secondary vein cooling channel will flow separately, and the flow boundary layer and the thermal boundary layer will redevelop. The redevelopment of the boundary layer will lead to an increase in the convective heat transfer coefficient in each cooling channel, thereby enhancing the cooling effect.

[0028] Secondly, the regenerative cooling channel inside the turbine blade adopts a layout of one coolant inlet and two coolant outlets as a whole, thereby achieving uniform flow of the internal cooling fluid, achieving the purpose of uniform cooling, and also improving the efficiency of convective heat transfer.

[0029] In addition, the cooling fluid that has cooled the turbine blades is finally transported to the combustion chamber for combustion. Since the cooling fluid is cracked during the cooling of the blades, the cooling fluid can release the heat absorbed during the cracking when entering the combustion chamber for combustion, thereby improving energy utilization.

Brief Description of the Drawings

[0030] Figure 1 It is a structural schematic diagram of a turbine blade with a bionic leaf-shaped regenerative cooling channel according to the present invention;

[0031] Figure 2 The figure is a schematic diagram of the layout of the regenerative cooling channels in a turbine blade having a bionic leaf-shaped regenerative cooling channel according to the present invention.

[0032] Among them, 101. blade leading edge, 102. blade body, 103. blade root, 104. blade top, 105. blade trailing edge; 201. main blade vein cooling channel, 202. secondary blade vein cooling channel, 203. transition cooling channel, 204. branch blade vein cooling channel, 205. outlet cooling channel, 206. coolant inlet, 207. coolant outlet. [Specific implementation method]

[0033] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] The present invention provides a turbine blade having a bionic leaf-shaped regenerative cooling channel, such as Figure 1 As shown, it includes a turbine blade and a bionic leaf-shaped regenerative cooling channel arranged in the blade, wherein the turbine blade has a blade body 102, one end of the blade body 102 is a blade root 103, and the other end is a blade tip 104. One side of the blade body 102 is a blade leading edge 101, and the other side is a blade trailing edge 105.

[0035] like Figure 2 As shown, the turbine blade body and the cooling channel are both axisymmetric structures. The bionic leaf-shaped regenerative cooling channel specifically includes:

[0036] An outlet cooling channel 205 is arranged in the blade body 102. It is a cooling channel that is arranged along the edges of the blade leading edge 101, the blade top 104 and the blade trailing edge 105. The cooling channel is an inverted U shape as a whole; the two intersections of the outlet cooling channel 205 and the blade root 103 are both coolant outlets 207.

[0037] A main vein cooling channel 201 is vertically arranged at the center of the blade body 102 along the direction from the blade root 103 to the blade top 104. The intersection of one end of the main vein cooling channel 201 and the blade root 103 is the coolant inlet 206, and the other end is not connected to the outlet cooling channel 205. Since the main vein cooling channel 201 acts as the inlet liquid collecting chamber of the cooling fluid here, it is necessary to ensure that the main vein cooling channel 201 is located in the middle of the blade, so as to ensure the uniform distribution of the flow rate, thereby achieving the purpose of uniform cooling of the blade. The inlet and outlet of the cooling fluid in the turbine blade adopts a one-in and two-out form, so that the flow trend of the cooling fluid in the upper and lower parts of the turbine blade is basically the same.

[0038] At least four secondary vein cooling channels 202 are symmetrically arranged on the left and right sides of the main vein cooling channel 201, and are all inclined toward the blade top 104. One end of each secondary vein cooling channel 202 is connected to the main vein cooling channel 201, and the other end is not connected to the outlet cooling channel 205.

[0039] At least two transition cooling channels 203 are symmetrically arranged on the left and right sides of the main vein cooling channel 201; each transition cooling channel 203 is located between two adjacent secondary vein cooling channels 202; one end of each transition cooling channel 203 is connected to the outlet cooling channel 205, and the other end is not connected to the main vein cooling channel 201.

[0040] A plurality of branch vein cooling channels 204 are channels branched off from the upper and lower sides of each secondary vein cooling channel 202. Among them, each branch vein cooling channel 204 below the two secondary vein cooling channels 202 near the blade root 103 extends to the left and right sides respectively and is connected to the outlet cooling channel 205, and each branch vein cooling channel 204 between each secondary vein cooling channel 202 and the adjacent transition cooling channel 203 converges to the transition cooling channel 203. Each branch vein cooling channel 204 above the two secondary vein cooling channels 202 near the blade top 104 is connected to the outlet cooling channel 205. The layout direction of the branch vein cooling channel 204 is mainly arranged according to the shape of the secondary vein cooling channel 202 and the blade. During the layout process, try to ensure that the length of a single cooling channel is not too long and the inclination angle is not too large.

[0041] The cross-sectional areas of the main blade cooling channel 201, the secondary blade cooling channel 202, the transition cooling channel 203 and the branch blade cooling channel 204 decrease step by step. This arrangement can ensure that a relatively suitable pressure difference is maintained between different channels, thereby driving the flow of the coolant. The multi-stage distributed cooling channel can exchange the convection heat exchange area as much as possible, change its heat exchange boundary, and finally achieve uniform cooling of the turbine blades.

[0042] During use, the coolant inlet 206 is used to introduce the cooling fluid, and the cooling fluid is uniformly transported to the outlet cooling channel 205 through the main vein cooling channel 201, the secondary vein cooling channel 202, the branch vein cooling channel 204 and the transition cooling channel 203 in sequence, and finally discharged through the two coolant outlets 207 to achieve cooling of the turbine blades.

[0043] In some embodiments, the secondary vein cooling channels 202 located on the same side of the primary vein cooling channel 201 are parallel to each other and spaced apart. The parallel and spaced arrangement can make the cooling fluid flow evenly in the channel, produce a uniform cooling effect, and the parallel and spaced arrangement helps prevent local overheating.

[0044] In some embodiments, each transition cooling channel 203 is parallel to the adjacent sub-vein cooling channel 202. The parallel arrangement of the transition cooling channel 203 and the sub-vein cooling channel 202 facilitates modular design, and the number of cooling channels can be increased or decreased as needed.

[0045] In some embodiments, each transition cooling channel 203 is located in the middle between two adjacent secondary blade vein cooling channels 202. Placing the transition cooling channel 203 in the middle can ensure uniform distribution of the cooling fluid, and arranging it in the middle position can reduce the flow distance of the cooling fluid in the channel and reduce pressure loss.

[0046] In some embodiments, each of the branch vein cooling channels 204 on the same side of each secondary blade vein cooling channel 202 is parallel to each other.

[0047] In some embodiments, the main vein cooling channel 201, the secondary vein cooling channel 202, the transition cooling channel 203 and the branch vein cooling channel 204 have the same cross-sectional shape, for example, the cross-sectional shape may be rectangular, square or circular.

[0048] Among them, when the cross-sectional shape is a rectangle, the long side lengths of the cross-sections of the main vein cooling channel 201, the secondary vein cooling channel 202, the transition cooling channel 203 and the branch vein cooling channel 204 are Lmain, Lsecondary, Ltransition and Lbranch respectively, then Lmain>Lsecondary>Ltransition>Lbranch; the width of the cross-section is designed according to the adaptability of the thickness of the blade.

[0049] In some embodiments, when the cross-sectional shape is a rectangle, the length of the long side of each branch vein cooling channel 204 is equal to the spacing width between two adjacent branch vein cooling channels 204. Such a setting can achieve uniform cooling and expand the cooling range.

[0050] In some embodiments, when the cross-sectional shape is a square, the side lengths of the cross-sections of the main vein cooling channel 201, the secondary vein cooling channel 202, the transition cooling channel 203 and the branch vein cooling channel 204 are respectively l main, l secondary, l transition and l branch, then l main > l secondary > l transition > l branch.

[0051] In some embodiments, when the cross-sectional shape is circular, the cross-sectional diameters of the main vein cooling channel 201, the secondary vein cooling channel 202, the transition cooling channel 203 and the branch vein cooling channel 204 are respectively Rmain, Rsecondary, Rtransition and Rbranch, then Rmain>Rsecondary>Rtransition>Rbranch.

[0052] In some embodiments, the cross-sectional dimensions are set to meet the following requirements:

[0053] L transition > 2L branch, L secondary > 2L transition, L main > 2L secondary;

[0054] Or, 1 transition > 21 branches, 1 secondary > 21 transitions, 1 main > 21 secondary;

[0055] Or, Rtransition>2Rbranch, Rsecondary>2Rtransition, Rmain>2Rsecondary.

[0056] The above dimensions are set to be more than twice the relationship, which can ensure a reasonable pressure difference between the two-stage cooling channels and the flow rate of the cooling fluid in the channels.

[0057] When arranging the cooling channel inside the turbine blade, the cooling channel should avoid being designed too narrow or too wide. A too narrow cooling channel will result in a higher flow resistance, and a too wide cooling channel may cause the cooling fluid to flow too fast in the center of the channel and flow too slowly near the wall of the cooling channel, thereby reducing the heat exchange efficiency. In order to ensure the pressure drop of the cooling channel inside the turbine blade, the present invention uses a large number of parallel branch vein cooling channels 204, and the flow length of a single branch vein cooling channel 204 is relatively short.

[0058] Take the example of setting four secondary vein cooling channels 202, where the cross-sectional shapes of the main vein cooling channel 201, the secondary vein cooling channel 202, the transition cooling channel 203 and the branch vein cooling channel 204 are all rectangular, and Lmain = X, Lsecondary = X / 4, Ltransition = X / 8, Lbranch = X / 16. It can be seen from this that the secondary vein cooling channel 202 belongs to the low-pressure area compared to the main vein cooling channel 201, and the fluid is driven by the pressure difference during the flow process. The pressure difference between the secondary vein cooling channel 202 and the main vein cooling channel 201 can ensure the flow rate of the cooling fluid and the stability of the flow. The size of the secondary vein cooling channel 202 is smaller than the main vein cooling channel 201. Therefore, when the cooling fluid enters the secondary vein cooling channel 202 from the main vein cooling channel 201 into four, the cooling fluid distribution can be guaranteed to be uniform, thereby ensuring that the turbine blades can be evenly cooled.

[0059] L Branch = L Times / 4. This arrangement can ensure the pressure gradient between the sub-vein cooling channel 202 and the branch vein cooling channel 204 during the flow of the cooling fluid, which can not only ensure the flow rate of the cooling fluid, but also ensure that the cooling fluid enters each branch vein cooling channel 204 evenly, thereby improving the convective heat exchange area and the cooling efficiency of the blade. L Transition = L Times / 2. The transition cooling channel 203 is connected to the outlet cooling channel 205, so the pressure of the transition cooling channel 203 is relatively small. Due to the pressure difference, the cooling fluid flows from the sub-vein cooling channel 202 through each branch vein cooling channel 204 and then merges into the transition cooling channel 203, and finally flows out of the turbine blade from the outlet cooling channel 205.

[0060] The two coolant outlets 207 can also be connected to the combustion chamber. When the cooling fluid is kerosene, the kerosene that has cooled the turbine blades will flow out from the two coolant outlets 207 and enter the combustion chamber for combustion. The kerosene that flows out of the turbine blades will enter the combustion chamber through the external pipeline and burn. Since the kerosene takes away the heat on the turbine blades when cooling the turbine blades, the kerosene can be cracked. When entering the combustion chamber for combustion, the heat absorbed during cracking can be released, thereby improving energy utilization and achieving regenerative cooling.

[0061] The present invention is a turbine blade suitable for a TBCC engine and having a bionic leaf-shaped regenerative cooling channel. The arrangement of the cooling channel is to simulate the shape of the leaf veins, the main leaf vein cooling channel 201 as the inlet liquid collecting cavity is arranged at a position similar to the main leaf vein of the leaf, and the arrangement of the remaining cooling channels is arranged in accordance with the secondary leaf veins and branch leaf veins of the leaf.

[0062] A plurality of turbine blades are evenly arranged on the turbine engine to form turbine blade channels. The turbine blades are in a hot environment formed by the high-temperature main combustion gas flow. A coolant inlet 206 and a coolant outlet 207 are arranged at the blade root of the turbine blade. The precooling cooling fluid flows in from the coolant inlet 206, flows through various cooling channels, removes the heat of the turbine blades through heat exchange, and then flows out of the turbine blades from the coolant outlet 207, thereby achieving the effect of cooling the turbine blades.

[0063] Embodiment: This embodiment is to Figure 2 The cooling effect of the turbine blade with the bionic leaf-shaped regenerative cooling channel of the structure shown was simulated and verified.

[0064] The cooling fluid is kerosene. Three different kerosene flow rates are used in the simulation analysis. The specific experimental data are shown in Table 1.

[0065] Table 1 Kerosene cooling simulation conditions and results

[0066]

[0067] Table 1 shows the kerosene cooling simulation working conditions of the turbine blade with the bionic leaf-shaped regenerative cooling channel of this embodiment. It can be seen from Table 1 that different kerosene flow rates can achieve better cooling effects on the blades. Generally speaking, the cooling temperature difference will also increase with the increase of kerosene flow rate. In actual use, the size of kerosene flow rate can be adjusted autonomously according to the cooling requirements of the blades.

[0068] Comparative example: This comparative example simulates and verifies the cooling effect of a turbine blade with a single rotary cooling channel. The cooling fluid in the single cooling channel is one inlet and one outlet, and the cooling fluid is kerosene, and the kerosene flow rate is set to 0.5kg / s. The initial temperature of the turbine blade surface is set to 1000K, and the convection heat transfer coefficient of the turbine blade surface is set to 2000W / (m 2 K), the kerosene inlet temperature is 300K.

[0069] From the simulation results of the comparative example, it can be seen that the temperature difference values ​​at the blade body, blade top, blade leading edge and blade trailing edge before and after the turbine blade is cooled are shown in Table 2.

[0070] From the data in Table 2, it can be seen that the temperature difference at the blade body is 70K~350K, and the cooling effect of the blade body is very uneven. The temperature difference at the blade top changes little, and the cooling effect is uneven. The temperature at the leading edge and trailing edge of the blade has basically not changed, and the cooling effect is not ideal.

[0071] Table 2 Comparison of cooling effects of the embodiments and comparative examples

[0072]

[0073] Since the single cooling channel commonly used in the prior art belongs to series cooling, a large cross-sectional area of ​​the cooling channel will cause the flow rate in the channel to be too fast, that is, the center flow rate of the cooling medium in the first half of the single cooling channel is faster, while the flow near the wall is too low, resulting in low heat exchange efficiency; while the flow rate in the second half of the single cooling channel is reduced, thereby improving the heat exchange efficiency. When the cross-sectional area of ​​the cooling channel is reduced and the length of the cooling channel is increased, the cooling medium will absorb more heat in the channel that flows through first, reducing the cooling efficiency of the subsequent channels and causing uneven cooling. Blockage or damage to any part of the series channel may cause the entire cooling system to fail.

[0074] The cooling effect of the comparative example and the present embodiment when the kerosene flow rate is 0.5kg / s is compared. The temperature difference of various parts of the blade after cooling in the present embodiment is shown in Table 2. From the data in Table 2, it can be seen that the temperature difference before and after the cooling of the blade body in the present embodiment is 180K~220K, and the cooling effect is good and uniform. The cooling effect at the blade top is more uniform than that of the comparative example. And because the present application arranges an outlet cooling channel 205 on the periphery of the turbine blade, the cooling effect near the leading edge and the trailing edge of the blade in the present embodiment is also improved to a certain extent compared with the comparative example.

[0075] Since the flow of the cooling fluid in a single cooling channel is driven only by the inlet and outlet pressure difference, and the cooling fluid in the turbine blade with a bionic leaf-shaped regenerative cooling channel of the present invention is driven by different pressure differences in different areas, and compared with a single channel, the flow boundary layer and the thermal boundary layer change more obviously, and a one-in-two-out layout is adopted to achieve enhanced cooling effect and uniform cooling. At the same time, the bionic leaf-shaped regenerative cooling channel adopted by the present invention belongs to parallel cooling, and the parallel cooling channel layout can ensure that each channel has enough cooling fluid, thereby improving the cooling efficiency. Moreover, even if one channel of the parallel cooling channel layout fails, the other channels can still continue to work, and the cooling system will not completely fail.

Claims

1. A turbine blade with a bionic leaf-shaped regenerative cooling channel, characterized in that: The invention comprises a turbine blade and a bionic leaf-shaped regenerative cooling channel arranged in the blade, wherein the turbine blade has a blade body (102); the bottom end and the top end of the blade body (102) are respectively a blade root (103) and a blade tip (104); the two sides of the blade body (102) are respectively a blade leading edge (101) and a blade trailing edge (105); The bionic leaf-shaped regenerative cooling channel comprises: an outlet cooling channel (205) disposed in the blade body (102), which is a cooling channel disposed through the edges of the blade leading edge (101), the blade top (104) and the blade trailing edge (105); two intersections of the outlet cooling channel (205) and the blade root (103) are both cooling liquid outlets (207); A main blade vein cooling channel (201) is vertically arranged at the inner center of the blade body (102); the intersection of one end of the main blade vein cooling channel (201) and the blade root (103) is a coolant inlet (206), and the other end is not connected to the outlet cooling channel (205); At least four secondary blade vein cooling channels (202) are symmetrically arranged on the left and right sides of the main blade vein cooling channel (201), and are all inclined toward the blade top (104); one end of each of the secondary blade vein cooling channels (202) is connected to the main blade vein cooling channel (201), and the other end is not connected to the outlet cooling channel (205); At least two transition cooling channels (203) are symmetrically arranged on the left and right sides of the main vein cooling channel (201); each of the transition cooling channels (203) is located between two adjacent secondary vein cooling channels (202); one end of each of the transition cooling channels (203) is connected to the outlet cooling channel (205), and the other end is not connected to the main vein cooling channel (201); A plurality of branch vein cooling channels (204), which are channels branched from the upper and lower sides of each of the secondary vein cooling channels (202); wherein each branch vein cooling channel (204) below the two secondary vein cooling channels (202) close to the blade root (103) extends to both sides and is connected to the outlet cooling channel (205); each branch vein cooling channel (204) between each of the secondary vein cooling channels (202) and the adjacent transition cooling channel (203) converges to the transition cooling channel (203); each branch vein cooling channel (204) above the two secondary vein cooling channels (202) close to the blade top (104) is connected to the outlet cooling channel (205); The cross-sectional areas of the main blade vein cooling channel (201), the secondary blade vein cooling channel (202), the transition cooling channel (203) and the branch blade vein cooling channel (204) decrease step by step; The coolant inlet (206) is used to introduce cooling fluid, and sequentially transport the cooling fluid evenly to the outlet cooling channel (205) through the main vein cooling channel (201), the secondary vein cooling channel (202), the branch vein cooling channel (204) and the transition cooling channel (203), and finally output the cooling fluid through the two coolant outlets (207) to complete the cooling of the turbine blades.

2. A turbine blade with a bionic leaf-shaped regenerative cooling channel according to claim 1, characterized in that: The secondary leaf vein cooling channels (202) located on the same side of the primary leaf vein cooling channel (201) are parallel to each other and arranged at intervals.

3. A turbine blade with a bionic leaf-shaped regenerative cooling channel as claimed in claim 2, characterized in that: Each of the transition cooling channels (203) is parallel to the adjacent secondary blade vein cooling channel (202).

4. The turbine blade with a bionic leaf-shaped regenerative cooling channel according to claim 3, characterized in that: Each of the transition cooling channels (203) is located in the middle between two adjacent secondary blade vein cooling channels (202).

5. A turbine blade with a bionic leaf-shaped regenerative cooling channel as claimed in claim 1 or 2, characterized in that: The branch vein cooling channels (204) located on the same side of each secondary vein cooling channel (202) are parallel to each other.

6. A turbine blade with a bionic leaf-shaped regenerative cooling channel as claimed in claim 1 or 2, characterized in that: The main blade vein cooling channel (201), the secondary blade vein cooling channel (202), the transition cooling channel (203) and the branch blade vein cooling channel (204) have the same cross-sectional shape; Wherein, when the cross-sectional shape is a rectangle, the lengths of the long sides of the cross-sections of the main vein cooling channel (201), the secondary vein cooling channel (202), the transition cooling channel (203) and the branch vein cooling channel (204) are Lmain, Lsecondary, Ltransition and Lbranch respectively, then Lmain>Lsecondary>Ltransition>Lbranch.

7. The turbine blade with a bionic leaf-shaped regenerative cooling channel according to claim 6, characterized in that: The length of the long side of the cross section of each of the branch vein cooling channels (204) is equal to the spacing width between two adjacent branch vein cooling channels (204).

8. The turbine blade with a bionic leaf-shaped regenerative cooling channel according to claim 6, characterized in that: When the cross-sectional shape is a square, assuming that the side lengths of the cross-sections of the main vein cooling channel (201), the secondary vein cooling channel (202), the transition cooling channel (203) and the branch vein cooling channel (204) are l main, l secondary, l transition and l branch respectively, then l main>l secondary>l transition>l branch.

9. The turbine blade with a bionic leaf-shaped regenerative cooling channel according to claim 8, characterized in that: When the cross-sectional shape is circular, the diameters of the cross-sectional dimensions of the main vein cooling channel (201), the secondary vein cooling channel (202), the transition cooling channel (203) and the branch vein cooling channel (204) are Rmain, Rsecondary, Rtransition and Rbranch, respectively, and Rmain>Rsecondary>Rtransition>Rbranch.

10. The turbine blade with a bionic leaf-shaped regenerative cooling channel according to claim 9, characterized in that: The cross-sectional dimensions are set to meet the following requirements: L transition > 2L branch, L secondary > 2L transition, L main > 2L secondary; Or, 1 transition > 21 branches, 1 secondary > 21 transitions, 1 main > 21 secondary; Or, Rtransition>2Rbranch, Rsecondary>2Rtransition, Rmain>2Rsecondary.

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