Rotor blade, compressor and wet compression method

Abstract

The present application discloses a rotor blade, a compressor and a wet compression method, wherein the rotor blade comprises: a blade body, the blade body comprises: a blade root, the blade root is used to be installed on the rotating shaft of the compressor, the blade root is provided with a water inlet, the water inlet is used to communicate with the water outlet on the rotating shaft, the water outlet of the rotating shaft is connected to the water outlet of the water spraying device; a blade top, the blade top is provided with a plurality of water spray holes, a water spray flow channel is provided inside the blade body, and each water spray hole is connected to the water inlet through the water spray flow channel. Spraying water into the compressor by the rotor blade proposed in the present application can not only form a water curtain to close the blade tip gap, but also play a role of wet compression, and the water is directly sprayed at the rotor blade tip, that is, directly sprayed into the compressor, the temperature inside the compressor is relatively high, and water directly sprayed into the compressor will not produce condensation.

Description

Technical Field

[0001] The present application relates to the field of gas turbines, and in particular to a rotor blade, a compressor and a wet compression method. Background Art

[0002] In the field of gas turbines, the rotor blades in the compressor, as a rotating mechanism, will inevitably have a tip gap with the inner wall of the casing. When air is inhaled, the tip gap will generate leakage flow driven by the pressure difference. The leakage flow of the tip gap will reduce the suction capacity of the airflow, and the leakage vortex generated by the airflow passing through the tip gap will also change the flow characteristics of the mainstream, increase flow losses, and reduce the performance of the compressor. At present, the method to reduce the tip gap leakage flow is mainly to reduce the tip gap, but if the tip gap is too small, it will cause the blades to rub against the casing.

[0003] In addition, in order to improve the performance of the compressor, the compressor often uses a wet compression method. The commonly used wet compression method in the prior art generally adds a water spray cooling device at the compressor air inlet and sprays water to the compressor air inlet. This method of directly adding a water spray device at the compressor air inlet will, on the one hand, cause the air flow at the compressor air inlet to be turbulent, affecting the stable operation of the compressor; on the other hand, the water spray device is located outside the compressor. If the ambient temperature outside the compressor is low, the water sprayed by the water spray device to the compressor air inlet is easy to condense. Summary of the invention

[0004] The present application proposes a rotor blade, a compressor and a wet compression method, aiming to solve the problem of compressor performance degradation caused by blade tip clearance leakage in the prior art, and the problem that the wet compression method in the prior art needs to add a water spray device at the compressor inlet position, thereby causing turbulent airflow and unstable operation at the compressor inlet, and the problem that water sprayed by the water spray device is easily condensed when the ambient temperature at the compressor inlet is low.

[0005] In an embodiment of the present application, a rotor blade is provided for use in a compressor, and the rotor blade includes:

[0006] The blade body comprises:

[0007] A blade root, the blade root is used to be installed on the rotating shaft of the compressor, the blade root is provided with a water inlet, the water inlet is used to communicate with the water outlet on the rotating shaft, and the water outlet of the rotating shaft is connected to the water outlet of the water spraying device;

[0008] The blade top is provided with a plurality of water spray holes, a water spray channel is provided inside the blade body, and each of the water spray holes is connected to the water inlet through the water spray channel.

[0009] In the embodiment of the present application, the water spray holes are evenly arranged along the length direction of the blade top, and the direction of each water spray hole is the same as the extension direction of the blade top.

[0010] In the embodiment of the present application, a plurality of the water inlets and the water spray channels are provided, each of the water inlets corresponds to each of the water spray channels one by one, and each of the water spray channels is connected at one end close to the blade top.

[0011] In the embodiment of the present application, each of the water spray holes is in the shape of a hole or a slit.

[0012] The present application also provides a compressor, wherein the compressor is provided with at least one rotor blade as described in any one of the above embodiments;

[0013] The compressor further comprises a rotating shaft, the rotating shaft is provided with a water outlet, each of the rotor blades is provided on the rotating shaft, and the water inlet of the rotor blade is communicated with the water outlet on the rotating shaft;

[0014] The water outlet of the rotating shaft is connected to the water spraying port of the water spraying device.

[0015] The present application also proposes a wet compression method, which is applied to the compressor described in the above embodiment, and the method comprises:

[0016] When the compressor is running, water is sprayed into the compressor through the water spray holes of each of the rotor blades according to a preset mass flow rate and a preset water drop size.

[0017] In the embodiment of the present application, the preset mass flow rate is calculated by the following formula: W=DM;

[0018] Wherein, W represents the sum of the mass flow rates of each water spray hole, D represents the moisture content of saturated air under the compressor outlet conditions, and M is the mass flow rate of the airflow passing through the compressor.

[0019] In the embodiment of the present application, the preset water drop size is calculated according to the following formula:

[0020]

[0021] Where, d represents the diameter of the water droplets sprayed by each water spray hole, L represents the distance between the water spray hole and the gas turbine combustion chamber, A is the throat area of ​​the last stage stator blade of the compressor, ρ is the air density at the compressor inlet, and π C is the compression ratio of the compressor, k is the air specific heat ratio, which is taken as 1.4, C is the evaporation coefficient of the water droplets, and π is the circular constant.

[0022] In the embodiment of the present application, the water is pure water.

[0023] In the embodiment of the present application, the water pressure of each of the water spray holes is greater than the air pressure in the compressor flow channel.

[0024] The rotor blades in the present application are provided with a water inlet at the blade root and a water spray hole at the blade top, so that water can be supplied to the water inlet of the rotor blade based on the water spray equipment and the water inlet flow channel of the rotating shaft is used, and water is sprayed out from the water spray hole. When the compressor is running, each rotor blade rotates at a high speed, and the water sprayed from the water spray hole at the blade top of each rotor blade can form a water curtain to close the blade top gap, so that the airflow cannot pass through the blade top gap, and thus the blade top gap leakage flow cannot be generated. In addition, using the rotor blades proposed in the present application, it is not necessary to set the water spray equipment at the air inlet position of the compressor during wet compression, and it can be set at any position that can be connected to the water inlet flow channel of the rotating shaft. Spraying water into the compressor through the rotor blades can not only form a water curtain to close the blade top gap, but also play a role in wet compression. Moreover, water is directly sprayed at the top of the rotor blade, that is, directly sprayed into the compressor. The temperature inside the compressor is relatively high, and water directly sprayed into the compressor will not produce condensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0026] Figure 1 is a schematic diagram of the structure of a rotor blade in an embodiment of the present application;

[0027] Figure 2 for Figure 1 A partial enlarged view of the tip of the rotor blade in FIG.

[0028] Figure 3 It is a cross-sectional view of a rotor blade in one embodiment of the present application. Description of the drawings:

[0030] 100 - blade body, 110 - blade top, 111 - water spray hole, 120 - blade root, 121 - water inlet, 122 - first water inlet, 123 - second water inlet, 124 - third water inlet, 130 - water spray channel, 131 - first water spray channel, 132 - second water spray channel, 133 - third water spray channel.

[0031] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0035] like Figure 1 , Figure 2 As shown, the embodiment of the present application provides a rotor blade, which is applied to a compressor, and the rotor blade includes:

[0036] The blade body 100 includes:

[0037] A blade root 120, the blade root 120 is used to be installed on the rotating shaft of the compressor, the blade root 120 is provided with a water inlet 121, the water inlet 121 is used to communicate with a water outlet on the rotating shaft, and the water outlet of the rotating shaft is connected to a water spraying port of a water spraying device;

[0038] The blade top 110 is provided with a plurality of water spray holes 111 . A water spray channel 130 is provided inside the blade body 100 . Each of the water spray holes 111 is connected to the water inlet 121 through the water spray channel 130 .

[0039] like Figure 1 As shown, in the embodiment of the present application, the general shape of the blade body 100 can be consistent with the shape of a common rotor blade in the prior art.

[0040] The blade body 100 is provided with a blade root 120. When installed in a compressor, the blade root 120 of the blade body 100 is connected to the rotating shaft of the compressor. The rotation of the rotating shaft drives the rotor blade to rotate, thereby compressing the airflow entering the compressor. Different from the rotor blades in the prior art, the rotor blades proposed in the embodiment of the present application are provided with a plurality of water inlets 121 at one end of the blade root 120, a plurality of water spray holes 111 at one end of the blade tip 110, and a water spray channel 130 is provided inside the blade body 100. Each water inlet 121 at one end of the blade root 120 is connected to each water spray hole 111 at one end of the blade tip 110 through the water spray channel 130.

[0041] By using the rotor blades proposed in the present application, a water outlet can be set on the rotating shaft of the compressor, and a water inlet channel can be set inside the rotating shaft. Water can be supplied to the water inlet channel of the rotating shaft by using a water spraying device. The water enters the water spraying channel 130 inside the blade body 100 through the water outlet of the rotating shaft and the water inlet 121 of the rotor blade, and can finally be sprayed out from the various water spray holes 111 on the blade top 110.

[0042] The tip 110 of the rotor blade is close to the inner wall of the compressor casing and has a tiny tip gap. The tip 110 of each rotor blade faces the inner wall of the casing. When each rotor blade rotates at high speed, each water spray hole 111 of each blade tip 110 sprays water, which can form a water curtain between the tip 110 of each blade and the inner wall of the casing. When the compressor is running, the rotor blades rotate at high speed, so each position of the tip gap in the circumferential direction can be filled with the water curtain sprayed by the water spray hole 111. Therefore, after each rotor blade rotates, the water sprayed by it forms a water curtain and can play a role in closing the tip gap. When the tip gap is closed, the airflow entering the compressor cannot pass through the tip gap, so no tip gap leakage flow can be generated.

[0043] In addition, after the water curtain formed by the water spraying holes 111 of each blade top 110 is scattered, it can meet the high-pressure airflow entering the compressor flow channel, and then be vaporized by the high-pressure airflow. It can absorb heat in the process of vaporization, thereby reducing the temperature of the air in the compressor flow channel, playing a role of wet compression, and improving the compression performance of the compressor.

[0044] The rotor blade in the present application is provided with a water inlet 121 at the blade root 120 and a water spray hole 111 at the blade top 110, so that based on the water spray equipment, water can be supplied to the water inlet 121 of the rotor blade by utilizing the water inlet channel of the rotating shaft, and sprayed out from the water spray hole 111. When the compressor is running, each rotor blade rotates at a high speed, and the water sprayed from the water spray hole 111 at the blade top 110 of each rotor blade can form a water curtain, closing the blade top gap, so that the airflow cannot pass through the blade top gap, and therefore no blade top gap leakage flow can be generated. In addition, by utilizing the rotor blades proposed in the present application, there is no need to set the water spraying equipment at the air inlet position of the compressor during wet compression. It can be set at any position that can be connected to the water inlet channel of the rotating shaft. Spraying water into the compressor through the rotor blades can not only form a water curtain to close the blade tip gap, but also play a role in wet compression. Moreover, water is directly sprayed out at the rotor blade tip 110, that is, directly sprayed into the compressor. The temperature inside the compressor is relatively high, and water directly sprayed into the compressor will not produce condensation.

[0045] like Figure 1 , Figure 2 , Figure 3 As shown, in the embodiment of the present application, the water spray holes 111 are evenly arranged along the length direction of the blade tip 110 , and the orientation of the water spray holes 111 is the same as the extension direction of the blade tip 110 .

[0046] Among them, a plurality of water spray holes 111 are evenly arranged in the length direction of the blade top 110, and each water spray hole 111 can spray water, and each water spray hole 111 can spray water at different positions, so as to ensure that the formed water curtain can completely close the blade top gap. In addition, each rotor blade is dispersedly arranged in the circumferential direction of the rotating shaft, and the direction of each rotor blade blade top 110 is perpendicular to the inner wall of the casing, and each water spray hole 111 has the same extension direction as the blade top 110, that is, each water spray hole 111 is also perpendicular to the inner wall of the casing, so the water sprayed by each water spray hole 111 is also perpendicular to the inner wall of the casing, and vertically spraying water to the inner wall of the casing is conducive to the formation of a water curtain.

[0047] like Figure 3 As shown, in the embodiment of the present application, the water inlet 121 and the water spray channel 130 are provided in plurality, each of the water inlet 121 corresponds to each of the water spray channels 130, and each of the water spray channels 130 is connected at one end close to the blade tip 110. Figure 3 As shown, in the embodiment of the present application, three water inlets 121 are provided on the end surface of the blade root 120. Figure 3 In the orientation shown, from left to right are the first water inlet 122, the second water inlet 123 and the third water inlet 124. Figure 3As shown, the interior of the blade body 100 is provided with a first water spray channel 131, a second water spray channel 132 and a third water spray channel 133 from left to right, the first water spray channel 131 is connected to the first water inlet 122, the second water spray channel 132 is connected to the second water inlet 123, and the third water spray channel 133 is connected to the third water inlet 124. Figure 3 As shown, the first water spray channel 131 , the second water spray channel 132 and the third water spray channel 133 merge at one end close to the blade tip 110 , and are connected to each water spray hole 111 of the blade tip 110 .

[0048] The water inlet 121 of the blade top 110 is connected to the water outlet of the water spraying device through the water outlet on the rotating shaft. The amount of water sprayed during wet compression is relatively large. If only one water inlet 121 is set at the blade root 120, a larger water inlet 121 needs to be set in order to ensure sufficient water spraying. When a larger water inlet 121 is set, the strength of the blade root 120 is reduced, thereby reducing the connection strength with the rotating shaft. In the embodiment of the present application, by evenly setting a plurality of smaller water inlets 121 on the blade root 120, sufficient water supply can be ensured, and a larger water inlet 121 can be avoided on the blade root 120, thereby not affecting the connection strength between the blade root 120 and the rotating shaft.

[0049] In addition, by setting three water spray channels 130 corresponding to the three water inlets 121 on the blade body 100, on the one hand, when water flows through the water spray channel 130 inside the blade body 100, the surface temperature of the blade can be lowered and the heat load of the blade can be reduced; on the other hand, if only one water spray channel 130 is set, the diameter of the water spray channel 130 needs to be larger, and the strength of the blade body 100 at the position of the water spray channel 130 is relatively weak. By setting multiple water spray channels 130 and distributing them at various positions of the blade body 100, the diameter of the water spray channel 130 can be relatively reduced to ensure the strength of the blade body 100.

[0050] In addition, it should be noted that in the embodiment of the present application, three water inlets 121 are provided on the blade root 120, and three water spray channels 130 are provided inside the blade body 100. In other embodiments, more or fewer water inlets 121 may be provided. The technical solution of the present application does not limit the specific number of water inlets 121. The number of water inlets 121 may be set according to the water supply required for wet compression of the gas turbine compressor. Moreover, the water spray channels 130 inside the blade body 100 may also be adaptively adjusted according to actual conditions, and the number of water spray channels 130 is not limited to be consistent with the number of water inlets 121.

[0051] like Figure 3As shown, in the embodiment of the present application, each of the water spray holes 111 may be in the shape of a hole, such as a perfect circular hole, an elliptical hole, a strip hole, etc. In other embodiments, it may also be in the shape of a slit, such as a slit, a gap, etc.

[0052] The present application also provides a compressor, which is provided with at least one rotor blade as described in any of the above embodiments;

[0053] The compressor further comprises a rotating shaft, the rotating shaft is provided with a water outlet, each of the rotor blades is provided on the rotating shaft, and the water inlet 121 of the rotor blade is communicated with the water outlet on the rotating shaft;

[0054] The water outlet of the rotating shaft is connected to the water spraying port of the water spraying device.

[0055] Since the compressor in the embodiment of the present application is provided with the rotor blades described in any of the above embodiments, the compressor proposed in the present application has at least all the beneficial effects of the above rotor blades, which will not be described one by one here.

[0056] The present application also proposes a wet compression method, which is applied to the compressor in the above embodiment, and the method comprises:

[0057] When the compressor is running, water is sprayed into the compressor through the water spray holes 111 of each of the rotor blades according to a preset mass flow rate and a preset water drop size.

[0058] Among them, when the compressor is performing wet compression, water is sprayed into the compressor. Water can reduce the temperature of the air inside the compressor. The lowered air temperature can increase the degree of compression of the air by the compressor, thereby improving the performance of the compressor. However, during the compressor compression process, if the amount of water sprayed is small, the temperature of the air cannot be fully reduced, and thus the compression performance of the compressor cannot be maximized; if the amount of water sprayed is large, the water will still be in a liquid state after flowing out of the compressor outlet with the air flow from the compressor, which will interfere with the combustion of the gas turbine combustion chamber. Therefore, it is necessary to control the flow rate of water sprayed into the compressor by the water spraying equipment so that it can be completely vaporized at the compressor outlet while maximally reducing the air temperature inside the compressor.

[0059] In the embodiment of the present application, the preset mass flow rate can be calculated by the following formula (1):

[0060] W=DM(1)

[0061] Wherein, W represents the sum of the mass flow rates of water sprayed by each water spray hole 111, D represents the moisture content of saturated air under the compressor outlet condition, and M represents the mass flow rate of the air flow passing through the compressor. Wherein, the outlet condition refers to the air pressure and temperature at the outlet of the compressor when the compressor is in working state.

[0062] Among them, W is the preset mass flow rate, which represents the sum of the masses of water sprayed by each water spray hole 111 per unit time. At this mass flow rate, the water sprayed by each water spray hole 111 per unit time can fully cool the air flowing into the compressor per unit time.

[0063] After determining the sum of the masses of water sprayed by each water spray hole 111 per unit time, it is also necessary to consider the size of the water droplets sprayed by each water spray hole 111. If the water droplets are large, although the air entering the compressor per unit time can be sufficiently cooled, due to the large water droplets, when the water droplets follow the air flow to reach the compressor outlet, they are still in a liquid state, which will interfere with subsequent combustion. Therefore, the diameter of the water droplets sprayed by each water spray hole 111 can be controlled so that the water droplets sprayed by each water spray hole 111 can be completely vaporized when they reach the compressor outlet.

[0064] In the embodiment of the present application, the preset water droplet diameter can be calculated according to the following formula (2):

[0065]

[0066] Wherein, d represents the diameter of the water droplets sprayed by each water spray hole 111, L represents the distance between the water spray hole 111 and the combustion chamber of the gas turbine, A is the throat area of ​​the last stage stator blade of the compressor, ρ is the air density at the compressor inlet, π C is the compression ratio of the compressor, k is the air specific heat ratio, which is taken as 1.4, C is the evaporation coefficient of the water droplets, and π is the circular constant.

[0067] The preset flow rate and the preset water droplet diameter can be determined by the above formulas (1) and (2). In the present application, water is sprayed into the compressor according to the preset mass flow rate and the preset water droplet diameter, which can fully cool the air entering the compressor while allowing the water droplets sprayed from each water spray hole 111 to be completely vaporized at the compressor outlet. In addition, the water droplets can also absorb heat after vaporization, thereby reducing the temperature of the airflow at the compressor outlet, thereby reducing the combustion temperature of the combustion chamber. At the same time, H 2 The increase in O content can also reduce gas turbine emissions.

[0068] In the embodiment of the present application, the water is pure water. Using pure water during wet compression can prevent the water droplets sprayed from each water spray hole 111 from damaging or corroding the internal structure of the compressor.

[0069] In the embodiment of the present application, the water pressure of each water spray hole 111 is greater than or equal to the air pressure in the compressor flow passage. The water pressure of each water spray hole 111 is set to be greater than the air pressure in the compressor flow passage to ensure that water droplets can be incident on the compressor flow passage.

[0070] The wet compression method proposed in the embodiment of the present application sprays water into the compressor according to the preset mass flow rate and the preset water droplet diameter, which can fully cool the air entering the compressor while allowing the water droplets sprayed from each water spray hole 111 to be completely vaporized at the compressor outlet. In addition, the water droplets can also absorb heat after vaporization, thereby reducing the temperature of the airflow at the compressor outlet, thereby reducing the combustion temperature of the combustion chamber, and at the same time, the H in the airflow 2 The increase in O content can also reduce gas turbine emissions.

[0071] The above description is only an optional embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A rotor blade, used in a compressor, characterized in that: include: The blade body comprises: A blade root, the blade root is used to be installed on the rotating shaft of the compressor, the blade root is provided with a water inlet, the water inlet is used to communicate with the water outlet on the rotating shaft, and the water outlet of the rotating shaft is connected to the water outlet of the water spraying device; A blade top, wherein the blade top is provided with a plurality of water spray holes, a water spray flow channel is provided inside the blade body, each of the water spray holes is connected to the water inlet through the water spray flow channel, and each of the water spray holes is perpendicular to the inner wall of the compressor casing; when each of the water spray holes on each blade top sprays water, a water curtain can be formed between the blade top of each blade and the inner wall of the casing; There are multiple water inlets and multiple water spray channels, each of which corresponds to each of the water inlets and water spray channels, and each of the water spray channels is connected at one end close to the blade top.

2. The rotor blade according to claim 1, characterized in that The water spray holes are evenly arranged along the length direction of the blade top, and the direction of each water spray hole is the same as the extension direction of the blade top.

3. The rotor blade according to claim 1, characterized in that Each of the water spray holes is in the shape of a hole or a slit.

4. A compressor, characterized in that: The compressor is provided with at least one rotor blade according to any one of claims 1 to 3; The compressor further comprises a rotating shaft, the rotating shaft is provided with a water outlet, each of the rotor blades is provided on the rotating shaft, and the water inlet of the rotor blade is communicated with the water outlet on the rotating shaft; The water outlet of the rotating shaft is connected to the water spraying port of the water spraying device.

5. A wet compression method, applied to the compressor as claimed in claim 4, characterized in that: The method comprises: When the compressor is running, water is sprayed into the compressor through the water spray holes of each of the rotor blades according to a preset mass flow rate and a preset water drop size.

6. The wet compression method according to claim 5, characterized in that: The preset mass flow rate is calculated by the following formula: W = DM; Wherein, W represents the sum of the mass flow rates of each water spray hole, D represents the moisture content of saturated air under the compressor outlet conditions, and M is the mass flow rate of the airflow passing through the compressor.

7. The wet compression method according to claim 5, characterized in that: The preset water drop size is calculated according to the following formula: Where, d represents the diameter of the water droplets sprayed by each water spray hole, L represents the distance between the water spray hole and the gas turbine combustion chamber, A is the throat area of ​​the last stage stator blade of the compressor, ρ is the air density at the compressor inlet, and π C is the compression ratio of the compressor, k is the air specific heat ratio, which is taken as 1.4, C is the evaporation coefficient of water droplets, π is the circular constant, and M is the mass flow rate of the airflow passing through the compressor.

8. The wet compression method according to any one of claims 5 to 7, characterized in that: The water is pure water.

9. The wet compression method according to any one of claims 5 to 7, characterized in that: The water pressure of each of the water spray holes is greater than the air pressure in the compressor flow channel.

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