Phase-by-phase hydraulic design method for impellers of gas-liquid multiphase pump

Abstract

A phase-by-phase hydraulic design method for impellers of a gas-liquid multiphase pump, comprising the following steps: determining design parameters of a gas-liquid multiphase pump; determining pressurization coefficients of different pressurization phases of the multiphase pump; on the basis of the pressurization coefficients of the different pressurization phases, determining hydraulic design parameters of the different pressurization phases one by one, the hydraulic design parameters comprising volumetric flow rates and pressurization values of the different pressurization phases; on the basis of the gas content of the impellers of the different pressurization phases, determining parameters of the impeller in each phase; and, on the basis of the parameters of the impeller in each phase, establishing an impeller model of the gas-liquid multiphase pump.

Description

A Method for Stage-by-Stage Hydraulic Design of Impellers for Multi-Stage Gas-Liquid Mixed Transport Pumps Technical Field

[0001] This invention relates to the field of fluid machinery design, and in particular to a method for the stage-by-stage hydraulic design of the impeller of a multi-stage gas-liquid mixed-transfer pump. Background Technology

[0002] Traditional oil and gas transportation often begins with gas-liquid separation, followed by separate pressurization of the gas and liquid phases by compressors and pumps before transportation. However, this method requires extensive equipment and long pipelines. Currently, a more advanced method involves using a gas-liquid mixing pump to mix and pressurize the gas and liquid phases, then transporting the mixture through a dedicated pipeline. This method significantly reduces pipeline installation and maintenance costs compared to traditional oil and gas separation. Consequently, gas-liquid mixing is being adopted by more oil and gas fields, leading to a growing demand for such pumps.

[0003] Gas-liquid mixed-phase pumps typically have high pressurization rates, often exist in multi-stage configurations, and transport media that are two-phase fluids with a high gas content. Therefore, unlike conventional multi-stage pumps transporting pure liquids, the design of multi-stage gas-liquid mixed-phase pumps needs to consider the issues of gas volume compression, flow rate reduction, and gas content decrease during the pump's progressive pressurization process. Thus, the impeller structural parameters of each stage should be adjusted to adapt to the progressively changing flow conditions. However, currently, a mature hydraulic design method for multi-stage gas-liquid mixed-phase pumps has not yet been established domestically or internationally. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a step-by-step hydraulic design method for impellers of multi-stage gas-liquid mixed-transfer pumps. By progressively modifying the hydraulic design of impellers between different booster stages, the structural parameters of different impeller stages can be determined, making multi-stage impeller hydraulic design more convenient and saving design time.

[0005] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0006] A method for stage-by-stage hydraulic design of impellers in a multi-stage gas-liquid mixed-transfer pump includes the following steps:

[0007] Determine the design parameters for a multi-stage gas-liquid mixed transport pump;

[0008] Determine the booster coefficients for different booster stages of a multi-stage mixed-transfer pump.

[0009] The hydraulic design parameters for different booster stages are determined step by step based on the booster coefficients of different booster stages, including the volumetric flow rate and booster value of different booster stages;

[0010] Based on the air content of different booster stage impellers, the parameters of each impeller stage are determined;

[0011] A multi-stage gas-liquid mixing pump impeller model was established based on the parameters of each impeller stage.

[0012] Furthermore, the design parameters of the multi-stage gas-liquid mixing pump include the inflow pressure P0 and the pump booster pressure P. T Volumetric flow rate Q, gas content α, and total number of booster stages n

[0013] Where, volumetric flow rate Q = Q l +Q g Q l Q is the liquid flow rate. g This refers to the gas flow rate;

[0014] Gas content α = Q g / Q.

[0015] Furthermore, the boosting coefficients of different boosting stages of the multi-stage mixed-transfer pump were determined, as follows:

[0016] Let the boosting coefficient of the i-th stage impeller be a. i If i∈(1,2,…,n), then the boosting capacity of each stage of the corresponding multi-stage mixed-transfer pump satisfies the following relationship:

[0017] in:

[0018] P i = The boost pressure value of the i-th stage impeller;

[0019] a1, a2, a3, ..., a n Let be the boost coefficient, and satisfy the following relationship:

[0020] The boost pressure value of the i-th stage impeller is:

[0021] The boost coefficient of the (i+1)th stage satisfies a i+1 =a i *b i b i The boost ratio of the i-th stage impeller ranges from 1.0 to 1.8.

[0022] The boost pressure value of the (i+1)th stage impeller is obtained.

[0023] The gas holdup α at the inlet of the (i+1)th stage impeller is obtained. i+1 The air content α of the (i+1)th stage impeller i+1 The expression is:

[0024] Determine if the boost coefficient for each stage meets the requirements. If the requirements are not met, adjust the boost coefficient of the first-stage impeller and the boost ratio of each stage until the boost coefficient of each stage meets the requirements.

[0025] Furthermore, the pressure boosting ratio b of the i-th stage impeller i The value ranges from 1.0 to 1.8; the boosting coefficient a1 of the first stage impeller ranges from 0.6 to 0.9; the higher the gas content at the inlet of the i-th stage impeller, the greater the boosting ratio of the i-th stage.

[0026] Furthermore, based on the i-th impeller pressure coefficient a i The hydraulic design parameters for different booster stages are determined step by step, including the volumetric flow rate and booster pressure for each booster stage, specifically as follows:

[0027] The boost pressure P of the i-th stage impeller i for:

[0028] The volumetric flow rate Q of the i-th stage impeller i It satisfies the following relationship:

[0029] Furthermore, when the gas content α of the i-th stage impeller... i When the air content is less than or equal to 10%, the parameters of each stage of the impeller are determined by the specific speed of the i-th stage impeller; when the air content α of the i-th stage impeller is... i When the value is greater than 10%, first determine the structural parameters of the first-stage impeller, and then correct the structural parameters of each stage impeller.

[0030] Furthermore, when the gas content α of the i-th stage impeller... i When the specific speed is less than or equal to 10%, the specific speed of the i-th stage impeller is calculated using the following formula:

[0031] Where: n s_i n is the specific speed of the i-th stage impeller; rotating ρ is the impeller speed; l The density of the liquid inside the pump;

[0032] Then, based on the obtained specific speed of the i-th stage impeller, the pump model is selected, and the structural parameters of the i-th stage impeller are determined.

[0033] Furthermore, when the gas content α of the i-th stage impeller... i When the value is greater than 10%, the structural parameters of the first-stage impeller are determined as follows:

[0034] Calculate the structural parameters of the first-stage impeller based on the boost pressure P1, volumetric flow rate Q, and air cutoff α1, including the inlet and outlet diameters D of the first-stage impeller. s_1 First-stage impeller hub equivalent diameter D h_1 First stage impeller inlet installation angle β j_1 First-stage impeller rim outlet placement angle βc_1 First-stage impeller hub cone angle θ1, first-stage blade wrap angle Specifically as follows:

[0035] First-stage impeller inlet and outlet diameter D s_1 :

[0036] Where: k0 is the first coefficient; n rotating The impeller speed;

[0037] First-stage impeller hub equivalent diameter D h_1 :D h_1 =d sh D s_1 ;

[0038] Where d sh The hub ratio;

[0039] The first-stage impeller rim inlet angle β j_1 :

[0040] Where: k1 is the second coefficient;

[0041] First-stage impeller rim outlet angle β c_1 :

[0042] Where k2 is the third coefficient; ρmix is ​​the gas-liquid mixture density, ρ mix =ρ l (1-α1)+ρ g α1; Δβ is the angle of attack;

[0043] The first-stage impeller hub cone angle θ1 = 6°~12°;

[0044] First-stage blade wrap angle

[0045] Furthermore, when the gas content α of the i-th stage impeller... i When the error exceeds 10%, the structural parameters of each impeller stage are adjusted as follows:

[0046] Each stage uses the same impeller inlet and outlet diameters and hub ratio;

[0047] The inlet angle β of the i-th stage impeller rim j_i The correction method satisfies the following equation:

[0048] The outlet angle β of the i-th stage impeller rim c_i The correction method satisfies the following equation:

[0049] The correction method for the i-th level hub cone angle satisfies the following formula: Where k3 is the fourth coefficient;

[0050] i-th stage blade wrap angle As the gas content decreases at each stage, then Gradually decrease.

[0051] An impeller for a multi-stage gas-liquid mixed-transfer pump is determined using the aforementioned multi-stage gas-liquid mixed-transfer pump impeller stage-by-stage hydraulic design method.

[0052] The beneficial effects of this invention are as follows:

[0053] This invention proposes a stage-by-stage hydraulic design method for multi-stage pump impellers to address the progressively changing influent conditions within multi-stage mixed-transfer pumps. This method allows for the full consideration of the variations in influent parameters at each stage during the pump design process, enabling the stage-by-stage design of structural parameters for each stage. This ensures that each impeller stage is better matched to the influent conditions at each stage, guaranteeing that each impeller stage operates within its high-efficiency range. This design method ensures the creation of more efficient multi-stage gas-liquid mixed-transfer pumps. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For those skilled in the art, it is obvious that other drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 is a flowchart of the multi-stage gas-liquid mixed-transfer pump impeller hydraulic design method of the present invention.

[0056] Figure 2 is an axial cross-sectional view of a mixed-transport pump impeller provided in an embodiment of the present invention.

[0057] Figure 3 is a schematic diagram of the inlet and outlet angles of the impeller rim of a mixed-transfer pump provided in an embodiment of the present invention.

[0058] Figure 4 is a schematic diagram of the blade wrap angle of a mixed-transport pump impeller provided in an embodiment of the present invention. Detailed Implementation

[0059] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0060] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0061] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] As shown in Figure 1, the multi-stage gas-liquid mixed-transfer pump impeller hydraulic design method of the present invention includes the following steps:

[0063] S01: Determine the design parameters of the multi-stage gas-liquid mixing pump, including volumetric flow rate, pump pressurization, and gas content;

[0064] The hydraulic design parameters of a multi-stage gas-liquid mixed-transfer pump include the inflow pressure P0 and the pump booster pressure P. T Volumetric flow rate Q, gas content α, and total number of booster stages n, where volumetric flow rate Q = Q l +Q g Q l Q is the liquid flow rate. g The gas flow rate is given by α; the gas content α = Q. g / Q. Here, the gas holdup α can be understood as the gas holdup of the first-stage impeller, i.e., α1.

[0065] S02: Determine the booster coefficients for different booster stages of the multi-stage mixed-transfer pump, as detailed below:

[0066] Let the boosting coefficient of the i-th stage impeller be a. i If i∈(1,2,…,n), then the boosting capacity of each stage of the corresponding multi-stage mixed-transfer pump satisfies the following relationship:

[0067] in:

[0068] P i = The boost pressure value of the i-th stage impeller;

[0069] a1, a2, a3, ..., a n Let be the boost coefficient, and satisfy the following relationship:

[0070] The boost coefficient of the (i+1)th stage satisfies a i+1 =a i *b i b i The boost ratio of the i-th stage impeller ranges from 1.0 to 1.8.

[0071] Generally, the boosting coefficient a1 of the first-stage impeller is 0.6 to 0.9. The higher the gas content, the smaller the a1 value should be. The higher the gas content at the inlet of the boosting stage, the greater the corresponding boosting ratio. When the gas content is less than 0.1, the boosting ratio is closer to 1.

[0072] The boost pressure value of the first-stage impeller is:

[0073] The inlet gas holdup of the second stage can be calculated based on the first-stage impeller pressurization value. The calculation method is as follows:

[0074] Then, based on the initial selection of the pressure ratio b2 corresponding to the second-stage inlet gas holdup α2, the pressure coefficient a2 of the second stage can be calculated; from a2, the pressure boost value P2 of the second stage can be calculated, and so on, to obtain the pressure boost value P of the (i+1)th stage impeller. i+1 The air content α of the (i+1)th stage impeller i+1 ,

[0075] The air content α of the (i+1)th stage impeller i+1 The expression is:

[0076] The boost ratio for each stage is selected sequentially, and the boost coefficient for each stage is calculated. Finally, it is determined whether the boost coefficient for each stage meets the requirements. If the requirements are not met, the boost coefficient of the first-stage impeller and the boost ratio of each stage are fine-tuned until the boost coefficient of each stage meets the requirements.

[0077] S03: Based on the i-th impeller pressure coefficient a i Determine the hydraulic design parameters for each booster stage step by step, including the volumetric flow rate and booster pressure for each booster stage:

[0078] The boost pressure P of the i-th stage impeller i for:

[0079] The volumetric flow rate Q of the i-th stage impeller i It satisfies the following relationship:

[0080] S04: Determination of parameters for each stage of the impeller

[0081] S04.1: When the air content α of the i-th stage impeller is... i When the specific speed is less than or equal to 10%, the specific speed of the i-th stage impeller can be calculated using the following formula:

[0082] Where: n s_i n is the specific speed of the i-th stage impeller; rotating ρ is the impeller speed; l The density of the liquid inside the pump;

[0083] Then, based on the obtained specific speed of the i-th stage impeller, the pump model is selected, and parameters such as the impeller diameter, hub ratio, blade inlet and outlet angles, hub cone angle, and blade wrap angle of the i-th stage impeller are determined.

[0084] S04.2: When the gas content α of the i-th stage impeller is... i When the value is greater than 10%, first determine the structural parameters of the first-stage impeller, and then correct the structural parameters of each stage impeller, as follows:

[0085] S04.2.1: Calculate the structural parameters of the first-stage impeller based on the boost pressure P1, volumetric flow rate Q, and air cutoff α1 of the first-stage impeller, including the inlet and outlet diameters D of the first-stage impeller. s_1 First-stage impeller hub equivalent diameter D h_1 First stage impeller inlet installation angle β j_1 First-stage impeller rim outlet placement angle β c_1 First-stage impeller hub cone angle θ1, first-stage blade wrap angle Specifically as follows:

[0086] First-stage impeller inlet and outlet diameter D s_1 :

[0087] Where: k0 is the first coefficient, k0 = 7~10; n rotating The impeller speed is given by k0; the selection of k0 is related to the flow rate and gas content.

[0088] First-stage impeller hub equivalent diameter D h_1 :D h_1 =d sh D s_1 ;

[0089] Where d sh The hub ratio; dsh =0.75~0.9, the higher the gas content, the larger the value;

[0090] The first-stage impeller rim inlet angle β j_1 :

[0091] Where: k1 is the second coefficient, k1 = 0.6 to 1.0;

[0092] First-stage impeller rim outlet angle β c_1 :

[0093] Where k2 is the third coefficient, k2 = 1.0~2.0; ρmix is ​​the gas-liquid mixture density, ρ mix =ρ l (1-α1)+ρ g α1; Δβ is the angle of attack, 0°~3°.

[0094] After obtaining the outlet angle of the first-stage impeller rim, the inlet and outlet angles for different blade heights are calculated using the formula dtanβ=constant.

[0095] The cone angle θ1 of the first-stage impeller hub is 6° to 12°. The higher the gas content, the larger the cone angle θ1.

[0096] First-stage blade wrap angle This value is related to the number of leaves and the gas content; the higher the gas content, the larger the leaf wrap angle.

[0097] S04.2.2: The structural parameters of different booster stage impellers are corrected using a step-by-step correction method, specifically as follows:

[0098] Each stage uses the same impeller inlet and outlet diameters and hub ratio;

[0099] The inlet angle β of the i-th stage impeller rim j_i The correction method satisfies the following equation:

[0100] The outlet angle β of the i-th stage impeller rim c_i The correction method satisfies the following equation:

[0101] The correction method for the i-th level hub cone angle satisfies the following formula:

[0102] Where k3 is the fourth coefficient, k3 = 0.8 to 1.2;

[0103] The selection method for the i-th level blade wrap angle satisfies the following criteria: blade wrap angle As the gas content decreases at each stage, then Gradually decrease.

[0104] S05: Determine the impeller hydraulic model of the multi-stage mixed-transfer pump based on the impeller structural parameters of different booster stages.

[0105] Example

[0106] Let's take the design parameters of a multistage pump as an example: incoming flow pressure 100,000 Pa, design flow rate 150 m³ / h. 3 / h, gas content 0.5, speed 3000r / min, required pressure boost 500000Pa, pump boosting stage 4.

[0107] S01: Determine the design parameters of the multi-stage gas-liquid mixing pump, including volumetric flow rate, pump booster pressure, and gas content, specifically:

[0108] Incoming flow pressure P0 = 1 atm; Mixed pump booster P T =5 atm; Volumetric flow rate Q = Q l +Q g =150m 3 / h; gas content α=0.5=α1; total number of booster stages n=4; impeller speed n rotating =3000 r / min. The volumetric flow rate Q is generally the volumetric flow rate Q1 of the first stage;

[0109] S02: Determine the booster coefficients for different booster stages of the multi-stage mixed-transfer pump, as detailed below:

[0110] Since the incoming gas content is relatively high (α = 0.5), a smaller first-stage boost coefficient (a1 = 0.7) is chosen, corresponding to the following first-stage boost value:

[0111] The corresponding gas content at the second-stage inlet is:

[0112] At this point, the gas content at the second-stage inlet is still relatively high. Choosing a second-stage boost ratio b2 = 1.5, the corresponding second-stage boost coefficient a2 is 1.05. Therefore, the second-stage boost value can be calculated as follows:

[0113] The gas content at the third inlet can be obtained as follows:

[0114] The gas holdup at the third inlet decreases to 0.239. Choosing a third boost ratio b3 = 1.2, the corresponding third-stage boost coefficient a3 is 1.26. Therefore, the third-stage boost value can be calculated as follows:

[0115] The gas content at the fourth inlet can be obtained as follows:

[0116] The gas content at the fourth inlet is reduced to 0.174. Considering that the total number of boosting stages is 4 and the total boosting value must be 500,000 Pa, the boosting value P4 of the fourth stage can be calculated to be 124,000 Pa. However, the boosting ratio b4 of the fourth stage is 0.787, which is not within the boosting range of 1 to 1.5. Therefore, the first-stage boosting coefficient a1 and the boosting ratio of each stage are revised according to the above steps. Thus, the boosting coefficient, boosting ratio and total boosting value of each stage are calculated to meet the constraints.

[0117] Through the above steps, the initial boost coefficient is adjusted to a1 = 0.6, and b2 = 1.5, b3 = 1.3, b4 = 1.14. The calculated boost coefficients for each stage are a2 = 0.9, a3 = 1.17, and a4 = 1.33.

[0118] Each boost coefficient meets the following requirements.

[0119] S03: Based on the i-th impeller pressure coefficient a i Determine the hydraulic design parameters for each booster stage step by step, including the volumetric flow rate and booster pressure for each booster stage:

[0120] The boost pressure P of the i-th stage impeller i for:

[0121] The volumetric flow rate Q of the i-th stage impeller i It satisfies the following relationship:

[0122] The calculations are shown in Table 1:

[0123] Table 1: Hydraulic Design Parameters for Multistage Pumps

[0124] S04: Determination of parameters for each stage of the impeller

[0125] As shown in Table 1, because the air content α of each impeller stage... i If all values ​​are greater than 10%, first determine the structural parameters of the first-stage impeller, and then correct the structural parameters of each stage impeller as follows:

[0126] The design parameters for the first-stage impeller are: P1 = 75000 Pa; Q = 150 m 3 / h; α1=0.5; n rotating =3000r / min;

[0127] First, as shown in Figures 2, 3, and 4, based on the volumetric flow rate and gas content, the first k0 = 8.32 is selected, and the inlet and outlet diameters D of the first-stage impeller are calculated. s_1 :

[0128] Secondly, choose d sh =0.875, then the equivalent diameter D of the impeller hub can be obtained. h_1 D h_1 =d sh D s_1 =0.875×200mm=175mm

[0129] Choosing k1 = 0.75, we can obtain the first-stage impeller rim inlet installation angle β. j_1 =6°;

[0130] Choosing k2 = 1.8 and the exit angle of attack Δβ = 2°, we obtain the first-stage impeller rim exit angle β. c_1 =13°;

[0131] The first-stage impeller hub cone angle θ1 = 8°, and the first-stage blade wrap angle

[0132] S04.2.2: The structural parameters of different booster stage impellers are corrected using a step-by-step correction method, specifically as follows:

[0133] Each stage uses the same impeller inlet and outlet diameters and hub ratio;

[0134] Based on the volumetric flow rate Q2 of the second-stage impeller, the inlet angle of the second-stage impeller rim is obtained as follows:

[0135] Similarly, the inlet angle β of the third-stage impeller rim can be calculated sequentially. j_3 = 4.9°, fourth stage impeller rim inlet angle β j_4 =4.7°.

[0136] Based on the gas content of the second-stage impeller, the boost pressure of the second-stage impeller, and the outlet angle of the first-stage impeller rim, the outlet angle β of the second-stage impeller rim is obtained. c_2 :

[0137] Similarly, the exit angle β of the third-stage impeller rim can be calculated sequentially. c_3 =11.8°, fourth-stage impeller rim outlet angle β j_4 =11.1°.

[0138] Based on the gas content of each stage and by selecting an appropriate k3, the hub cone angles for each stage can be calculated as follows: second stage hub cone angle θ2 = 6.5°, third stage hub cone angle θ3 = 5.5°, and fourth stage hub cone angle θ4 = 4.5°.

[0139] The blade wrap angles selected for the second, third, and fourth levels are as follows: Second-level blade wrap angle Third-stage blade wrap angle Fourth-stage blade wrap angle

[0140] The impeller hydraulic structure parameters of all booster stages in the multistage pump were determined, and the results are shown in Table 2.

[0141] Table 2: Structural Parameters of Stage-by-Stage Impellers in Multistage Pumps

[0142] S05: Determine the impeller hydraulic model of the multi-stage mixed-transfer pump based on the impeller structural parameters of different booster stages.

[0143] An impeller for a multi-stage gas-liquid mixed-transfer pump, which is determined using the step-by-step hydraulic design method for multi-stage gas-liquid mixed-transfer pump impellers described in this invention.

[0144] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0145] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for stage-by-stage hydraulic design of the impeller of a multi-stage gas-liquid mixed-transfer pump, characterized in that, Includes the following steps: Determine the design parameters for a multi-stage gas-liquid mixed transport pump; Determine the booster coefficients for different booster stages of a multi-stage mixed-transfer pump. The hydraulic design parameters for different booster stages are determined step by step based on the booster coefficients of different booster stages, including the volumetric flow rate and booster value of different booster stages; The structural parameters of each stage impeller are determined based on the air content of different booster stage impellers; A multi-stage gas-liquid mixing pump impeller model was established based on the impeller structural parameters of each stage.

2. The multi-stage gas-liquid mixed-transfer pump impeller stage-by-stage hydraulic design method according to claim 1, characterized in that, The design parameters of a multi-stage gas-liquid mixing pump include the inflow pressure P0 and the pump booster pressure P. T Volumetric flow rate Q, gas content α, and total number of booster stages n Where, volumetric flow rate Q = Q l +Q g Q l Q is the liquid flow rate. g This refers to the gas flow rate; Gas content α = Q g / Q.

3. The multi-stage gas-liquid mixed-transfer pump impeller stage-by-stage hydraulic design method according to claim 1, characterized in that, The booster coefficients for different booster stages of a multi-stage mixed-transfer pump are determined as follows: Let the boosting coefficient of the i-th stage impeller be a. i If i∈(1,2,…,n), then the boosting capacity of each stage of the corresponding multi-stage mixed-transfer pump satisfies the following relationship: in: P i = The boost pressure value of the i-th stage impeller; a1, a2, a3, ..., a n Let be the boost coefficient, and satisfy the following relationship: The boost pressure value of the i-th stage impeller is: The boost coefficient of the (i+1)th stage satisfies a i+1 =a i *b i b i The boost ratio of the i-th stage impeller ranges from 1.0 to 1.

8. The boost pressure value of the (i+1)th stage impeller is obtained. The gas holdup α at the inlet of the (i+1)th stage impeller is obtained. i+1 The air content α of the (i+1)th stage impeller i+1 The expression is: Determine if the boost coefficient for each stage meets the requirements. If the requirements are not met, adjust the boost coefficient of the first-stage impeller and the boost ratio of each stage until the boost coefficient of each stage meets the requirements.

4. The multi-stage gas-liquid mixed-transfer pump impeller stage-by-stage hydraulic design method according to claim 3, characterized in that, The pressure boost ratio b of the i-th stage impeller i The value ranges from 1.0 to 1.8; the boosting coefficient a1 of the first stage impeller ranges from 0.6 to 0.9; the higher the gas content at the inlet of the i-th stage impeller, the greater the boosting ratio of the i-th stage.

5. The multi-stage gas-liquid mixed-transfer pump impeller hydraulic design method according to claim 1, characterized in that, According to the pressure boosting coefficient a of the i-th impeller i The hydraulic design parameters for different booster stages are determined step by step, including the volumetric flow rate and booster pressure for each booster stage, specifically as follows: The boost pressure P of the i-th stage impeller i for: The volumetric flow rate Q of the i-th stage impeller i It satisfies the following relationship:

6. The multi-stage gas-liquid mixed-transfer pump impeller stage-by-stage hydraulic design method according to claim 1, characterized in that, When the air content α of the i-th stage impeller i When the air content is less than or equal to 10%, the parameters of each stage of the impeller are determined by the specific speed of the i-th stage impeller; when the air content α of the i-th stage impeller is... i When the percentage is greater than 10%, the hydraulic design method for mixed-transport pumps proposed in this patent is used for stage-by-stage design.

7. The multi-stage gas-liquid mixed-transfer pump impeller stage-by-stage hydraulic design method according to claim 6, characterized in that, When the air content α of the i-th stage impeller i When the specific speed is less than or equal to 10%, the specific speed of the i-th stage impeller is calculated using the following formula: Where: n s_i n is the specific speed of the i-th stage impeller; rotating ρ is the impeller speed; l The density of the liquid inside the pump; Then, based on the obtained specific speed of the i-th stage impeller, the pump model is selected, and the structural parameters of the i-th stage impeller are determined.

8. The multi-stage gas-liquid mixed-transfer pump impeller stage-by-stage hydraulic design method according to claim 6, characterized in that, When the air content α of the i-th stage impeller i When the value is greater than 10%, the structural parameters of the first-stage impeller are determined as follows: Calculate the structural parameters of the first-stage impeller based on the boost pressure P1, volumetric flow rate Q, and air cutoff α1, including the inlet and outlet diameters D of the first-stage impeller. s_1 First-stage impeller hub equivalent diameter D h_1 First stage impeller inlet installation angle β j_1 First-stage impeller rim outlet placement angle β c_1 First-stage impeller hub cone angle θ1, first-stage blade wrap angle Specifically as follows: First-stage impeller inlet and outlet diameter D s_1 : Where: k0 is the first coefficient; n rotating The impeller speed; First-stage impeller hub equivalent diameter D h_1 :D h_1 =d sh D s_1 ; Where d sh The hub ratio; The first-stage impeller rim inlet angle β j_1 : Where: k1 is the second coefficient; First-stage impeller rim outlet angle β c_1 : Where k2 is the third coefficient; ρ mix ρ is the density of the gas-liquid mixture. mix =ρ l (1-α1)+ρ g α1; Δβ is the angle of attack; The first-stage impeller hub cone angle θ1 = 6°~12°; First-stage blade wrap angle 9. The multi-stage gas-liquid mixed-transfer pump impeller stage-by-stage hydraulic design method according to claim 6, characterized in that, When the air content α of the i-th stage impeller i When the error exceeds 10%, the structural parameters of each impeller stage are adjusted as follows: Each stage uses the same impeller inlet and outlet diameters and hub ratio; The inlet angle β of the i-th stage impeller rim j_i The correction method satisfies the following equation: The outlet angle β of the i-th stage impeller rim c_i The correction method satisfies the following equation: The correction method for the i-th level hub cone angle satisfies the following formula: Where k3 is the fourth coefficient; i-th stage blade wrap angle As the gas content decreases at each stage, then Gradually decrease.

10. An impeller for a multi-stage gas-liquid mixed-transfer pump, characterized in that, The impeller is determined using the stage-by-stage hydraulic design method for the multi-stage gas-liquid mixed-transfer pump according to any one of claims 1-9.

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