CN107194198B - Axial thrust calculation method and device for closed impeller of centrifugal compressor and storage medium - Google Patents

Abstract

The invention discloses a method and a device for calculating axial thrust of a closed impeller of a centrifugal compressor, relates to the technical field of centrifugal compressors, and can improve the accuracy of the axial thrust of the closed impeller of the centrifugal compressor. The method comprises the following steps: respectively calculating a first axial thrust of static pressure of air at an inlet of the impeller to the impeller, a second axial thrust of static pressure of clearance air at the outer side of a wheel cover of the impeller to the impeller, a third axial thrust of clearance air at the outer side of a wheel disc of the impeller to the impeller, and a fourth axial thrust of axial momentum change of air at an inlet and an outlet of the impeller to the impeller; and determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust. The method is suitable for calculating the axial thrust of the closed impeller of the centrifugal compressor.

Description

Axial thrust calculation method and device for closed impeller of centrifugal compressor and storage medium

Technical Field

The invention relates to the technical field of centrifugal compressors, in particular to a method and a device for calculating axial thrust of a closed impeller of a centrifugal compressor.

Background

Centrifugal compressors are typically multi-stage, which can achieve higher gas pressures, higher throughput, and higher efficiency. The calculation of the axial thrust of the closed impeller of the centrifugal compressor has important significance for the fault prediction of the centrifugal compressor, for example, the faults of overhigh temperature of a thrust pad, abrasion of a thrust bearing pad, seal damage, contact and mutual abrasion of a rotor and a partition plate and the like can be caused due to overhigh axial thrust of the impeller.

At present, the axial thrust of the closed impeller of the centrifugal compressor has a lot of influence factors, however, the existing calculation method of the axial thrust of the closed impeller of the centrifugal compressor is too simple, the considered influence factors are few, and the calculation accuracy of the axial thrust of the closed impeller of the centrifugal compressor is influenced.

Disclosure of Invention

In view of this, the invention provides a method and a device for calculating the axial thrust of a closed impeller of a centrifugal compressor, and mainly aims to calculate the axial thrust of the closed impeller by combining multiple influence factors of the axial thrust of the closed impeller of the centrifugal compressor, and improve the accuracy of the axial thrust of the closed impeller of the centrifugal compressor.

According to one aspect of the invention, a method for calculating axial thrust of a closed impeller of a centrifugal compressor is provided, and the method comprises the following steps:

respectively calculating a first axial thrust of static pressure of air at an inlet of the impeller to the impeller, a second axial thrust of static pressure of clearance air at the outer side of a wheel cover of the impeller to the impeller, a third axial thrust of clearance air at the outer side of a wheel disc of the impeller to the impeller, and a fourth axial thrust of axial momentum change of air at an inlet and an outlet of the impeller to the impeller;

and determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust.

Specifically, calculate impeller import aerostatic pressure respectively to the first axial thrust of impeller, impeller wheel cap outside clearance aerostatic pressure to the second axial thrust of impeller, impeller rim plate outside clearance gas to the third axial thrust of impeller, impeller import and export the change of gas axial momentum fourth axial thrust to the impeller, specifically include:

determining first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller according to the radial distribution of the static pressure at the inlet of the impeller, the diameter of a front spacer sleeve of the impeller and the axial distribution of the static pressure at the outlet of the impeller;

determining the second axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the gap gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step-type sealing condition;

determining a third axial thrust of the gap gas at the outer side of the impeller wheel disc to the impeller according to the centrifugal force and the pressure distribution;

and determining the fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller to the impeller according to the axial momentum change of the gas at the inlet and the outlet of the impeller, the flow coefficient of an operating working condition point of the impeller, the flow coefficient of a high-efficiency point of the impeller, the outer diameter of the impeller, the Mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller.

Specifically, according to the radial distribution of static pressure at an impeller inlet, the diameter of a spacer bush in front of the impeller and the axial distribution of static pressure at an impeller outlet, determining the first axial thrust of the static pressure of gas at the impeller inlet to the impeller, specifically comprising:

and calculating the first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller by using a first predetermined formula by taking the minimum diameter of the sealing step of the opening ring of the impeller, the diameter of the front spacer sleeve of the impeller, the maximum static pressure of the impeller in the radial direction, the radial distribution of the static pressure at the inlet of the impeller, the machine Mach number of the impeller and the reference machine Mach number of the impeller as parameters.

Specifically, the first predetermined formula is

Wherein D is_1dMinimum diameter of sealing step for impeller lip ring, D_jFor the front spacer sleeve of the impeller to be straightDiameter, p₀Maximum static pressure, ζ, of the impeller in the radial direction_in(r) is the radial distribution of the static pressure at the inlet of the impeller, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₁Is the first axial thrust.

Specifically, according to centrifugal force generated by rotation of gap gas of gas outside the wheel cover of the impeller, pressure distribution caused by leakage of a wheel cover opening ring and the step-type sealing condition, determining the second axial thrust of static pressure of the gap gas outside the wheel cover of the impeller to the impeller, specifically comprising:

and calculating the second axial thrust of the static pressure of the gap gas outside the impeller cover on the impeller by using a second preset formula and taking the diameter of the impeller, the maximum diameter of the sealing step of the impeller opening ring, the static pressure correction coefficient of the gap inlet outside the impeller cover, the radial variation rule of the static pressure outside the impeller cover, the machine Mach number of the impeller, the reference machine Mach number of the impeller as parameters, the minimum diameter of the sealing step of the impeller opening ring, the radial maximum static pressure of the impeller, the static pressure of the outlet of the impeller and the radial variation rule of the static pressure of the sealing step of the impeller opening ring as parameters.

Specifically, the second predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_1uMaximum diameter of sealing step for impeller lip ring, β_outFor the static pressure correction coefficient, p, of the entrance to the outboard gap of the wheel cover_fZeta impeller exit static pressure_sout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refMach number of reference machine, D, for impeller_1dFor minimum diameter of sealing step of impeller mouth ring, P₀Maximum static pressure, ζ, of the impeller in the radial direction_sout(r_1u) For the static pressure of sealing steps of the impeller mouth ring to change along the radial direction, F₂Is the second axial thrust.

Specifically, according to the centrifugal force and the pressure distribution, determining a third axial thrust of the gap gas outside the impeller wheel disc to the impeller specifically includes:

and calculating a third axial thrust of the clearance gas outside the wheel disc of the impeller to the impeller by using a third preset formula by taking the diameter of the impeller, the diameter of a rear spacer sleeve of the impeller, the static pressure correction coefficient of an inlet of a clearance on the outer side of the wheel disc, the static pressure of an outlet of the impeller, the radial variation rule of the static pressure on the outer side of a wheel cover of the impeller, the machine Mach number of the impeller and the reference machine Mach number of the impeller as parameters.

Specifically, the third predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_mIs the diameter of the impeller back spacer, gamma_outIs a static pressure correction coefficient, p, of the gap entrance at the outer side of the wheel disc_fZeta impeller exit static pressure_hout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₃Is the third axial thrust.

Specifically, according to the change of the axial momentum of the gas at the inlet and the outlet of the impeller, the flow coefficient of the operating condition point of the impeller, the flow coefficient of the high efficiency point of the impeller, the outer diameter of the impeller, the mach number of the impeller, the static pressure at the inlet of the impeller and the gas at the inlet of the impeller, the fourth axial thrust of the change of the axial momentum of the gas at the inlet and the outlet of the impeller to the impeller is determined, and the method:

and calculating fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller on the impeller by using a fourth predetermined formula by taking the mass flow of the impeller, the axial speed of the gas at the inlet of the impeller, the axial speed of the gas at the outlet of the impeller, the flow coefficient of a high-efficiency point of a reference impeller, the actual flow coefficient of the impeller, the diameter of the impeller, the reference diameter of the impeller, the machine Mach number of the impeller, the reference machine Mach number of the impeller, the inlet static pressure of the impeller, the inlet reference static pressure of the impeller, the volume entropy index, the reference value of the volume entropy index and the reference value of the axial thrust generated by the axial momentum change.

Specifically, the fourth predetermined formula is

Wherein Q is_mIs the mass flow rate of the impeller, V_zinIs the axial velocity, V, of the impeller inlet air flow_zoutIs the axial velocity of the impeller outlet flow, phi_1BEPFlow coefficient of impeller high efficiency point, phi_1BEPrefFor reference to the flow coefficient of the high efficiency point of the impeller, phi₁Is the actual flow coefficient of the impeller, D₂Is the diameter of the impeller, D_2refReference diameter of the impeller, Ma machine Mach number of the impeller, Ma_refReference machine Mach number, P, of the impeller_inIs the inlet static pressure, P, of the impeller_inrefIs the inlet reference static pressure of the impeller, Kv is the volume constant entropy index, Kv_refFor reference values of volume constant entropy index, F_4BEPrefIs a reference value of axial thrust generated by the impeller by the change of axial momentum of gas at the inlet and the outlet of the impeller, F₄Is the fourth axial thrust.

Specifically, determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust specifically includes:

and subtracting the first axial thrust from the third axial thrust, subtracting the second axial thrust from the third axial thrust, subtracting the fourth axial thrust from the third axial thrust, and taking the difference value obtained finally as the total axial thrust of the impeller.

According to another aspect of the present invention, there is provided a centrifugal compressor closed impeller axial thrust calculating device, comprising:

the calculation unit is used for respectively calculating a first axial thrust of static pressure of air at an inlet of the impeller to the impeller, a second axial thrust of static pressure of clearance air at the outer side of a wheel cover of the impeller to the impeller, a third axial thrust of clearance air at the outer side of a wheel disc of the impeller to the impeller and a fourth axial thrust of axial momentum change of air at an inlet and an outlet of the impeller to the impeller;

and the determining unit is used for determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust.

Specifically, the calculation unit is specifically configured to determine a first axial thrust of the static pressure of the impeller inlet to the impeller according to radial distribution of the static pressure of the impeller inlet, the diameter of the impeller front spacer, and axial distribution of the static pressure of the impeller outlet;

determining the second axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the gap gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step-type sealing condition;

determining a third axial thrust of the gap gas at the outer side of the impeller wheel disc to the impeller according to the centrifugal force and the pressure distribution;

and determining the fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller to the impeller according to the axial momentum change of the gas at the inlet and the outlet of the impeller, the flow coefficient of an operating working condition point of the impeller, the flow coefficient of a high-efficiency point of the impeller, the outer diameter of the impeller, the Mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller.

Specifically, the calculation unit is further configured to calculate a first axial thrust of the static pressure of the inlet gas of the impeller to the impeller by using a first predetermined formula, with parameters of a minimum diameter of a sealing step of the mouth ring of the impeller, a diameter of a front spacer of the impeller, a maximum static pressure of the impeller in a radial direction, a radial distribution of the static pressure at the inlet of the impeller, a machine mach number of the impeller, and a reference machine mach number of the impeller.

Specifically, the first predetermined formula is

Wherein D is_1dMinimum diameter of sealing step for impeller lip ring, D_jIs the diameter of the impeller front spacer, p₀Maximum static pressure, ζ, of the impeller in the radial direction_in(r) is the radial distribution of the static pressure at the inlet of the impeller, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₁Is the first axial thrust.

Specifically, the calculation unit is further configured to calculate a second axial thrust of the static pressure of the gap gas outside the impeller cover to the impeller by using a second predetermined formula, with parameters of a diameter of the impeller, a maximum diameter of the seal step of the impeller opening ring, a static pressure correction coefficient of a gap inlet outside the impeller cover, a radial variation rule of the static pressure outside the impeller cover, a machine mach number of the impeller, a reference machine mach number of the impeller, a minimum diameter of the seal step of the impeller opening ring, a radial maximum static pressure of the impeller, an impeller outlet static pressure, and a radial variation rule of the static pressure of the seal step of the impeller opening ring.

Specifically, the second predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_1uMaximum diameter of sealing step for impeller lip ring, β_outFor the static pressure correction coefficient, p, of the entrance to the outboard gap of the wheel cover_fZeta impeller exit static pressure_sout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refMach number of reference machine, D, for impeller_1dFor minimum diameter of sealing step of impeller mouth ring, P₀Maximum static pressure, ζ, of the impeller in the radial direction_sout(r_1u) For the static pressure of sealing steps of the impeller mouth ring to change along the radial direction, F₂Is the second axial thrust.

Specifically, the calculation unit is further configured to calculate a third axial thrust of the gap gas outside the wheel disc of the impeller to the impeller by using a third predetermined formula with parameters of an impeller diameter, an impeller back spacer diameter, a static pressure correction coefficient of a gap inlet on the outer side of the wheel disc, an impeller outlet static pressure, a radial variation rule of a static pressure on the outer side of a wheel cover of the impeller, a machine mach number of the impeller, and a reference machine mach number of the impeller.

Specifically, the third predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_mIs the diameter of the impeller back spacer, gamma_outIs a static pressure correction coefficient, p, of the gap entrance at the outer side of the wheel disc_fZeta impeller exit static pressure_hout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₃Is the third axial thrust.

Specifically, the calculating unit is further configured to calculate, using a fourth predetermined formula, a fourth axial thrust of the change of the axial momentum of the gas at the inlet and the outlet of the impeller to the impeller, using the mass flow of the impeller, the axial speed of the gas at the inlet of the impeller, the axial speed of the gas at the outlet of the impeller, the flow coefficient of the high-efficiency point of the reference impeller, the actual flow coefficient of the impeller, the diameter of the impeller, the reference diameter of the impeller, the machine mach number of the impeller, the reference machine mach number of the impeller, the inlet static pressure of the impeller, the inlet reference static pressure of the impeller, the volume entropy index, the reference value of the volume entropy index, and the reference value of the axial thrust of the change of the.

Specifically, the fourth predetermined formula is

Wherein Q is_mIs the mass flow rate of the impeller, V_zinIs the axial velocity, V, of the impeller inlet air flow_zoutIs the axial velocity of the impeller outlet flow, phi_1BEPFlow coefficient of impeller high efficiency point, phi_1BEPrefFor reference to the flow coefficient of the high efficiency point of the impeller, phi₁Is the actual flow coefficient of the impeller, D₂Is the diameter of the impeller, D_2refReference diameter of the impeller, Ma machine Mach number of the impeller, Ma_refReference machine Mach number, P, of the impeller_inIs the inlet static pressure, P, of the impeller_inrefIs the inlet reference static pressure of the impeller, Kv is the volume constant entropy index, Kv_refFor reference values of volume constant entropy index, F_4BEPrefIs a reference value of axial thrust generated by the impeller by the change of axial momentum of gas at the inlet and the outlet of the impeller, F₄Is the fourth axial thrust.

Specifically, the determining unit is specifically configured to subtract the first axial thrust from the third axial thrust, subtract the second axial thrust from the third axial thrust, subtract the fourth axial thrust from the third axial thrust, and obtain a difference value serving as an impeller axial total thrust.

According to yet another aspect of the invention, there is provided a computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:

respectively calculating a first axial thrust of static pressure of air at an inlet of the impeller to the impeller, a second axial thrust of static pressure of clearance air at the outer side of a wheel cover of the impeller to the impeller, a third axial thrust of clearance air at the outer side of a wheel disc of the impeller to the impeller, and a fourth axial thrust of axial momentum change of air at an inlet and an outlet of the impeller to the impeller;

and determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust.

According to a further aspect of the present invention, there is provided a physical device for closed impeller axial thrust calculation of a centrifugal compressor, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

respectively calculating a first axial thrust of static pressure of air at an inlet of the impeller to the impeller, a second axial thrust of static pressure of clearance air at the outer side of a wheel cover of the impeller to the impeller, a third axial thrust of clearance air at the outer side of a wheel disc of the impeller to the impeller, and a fourth axial thrust of axial momentum change of air at an inlet and an outlet of the impeller to the impeller;

and determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust.

By means of the technical scheme, compared with the existing closed impeller axial thrust calculation method of the centrifugal compressor, the closed impeller axial thrust calculation method and the closed impeller axial thrust calculation device of the centrifugal compressor provided by the invention have the advantages that the axial thrust of the closed impeller of the centrifugal compressor can be comprehensively calculated by combining the influences of the static pressure of impeller inlet gas, the static pressure of impeller wheel cover outer side gap gas, the impeller wheel disc outer side gap gas and the change of impeller inlet and outlet gas axial momentum on the impeller, the factors are more comprehensive, the existing axial thrust calculation method is perfected, and the calculation accuracy is greatly improved.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 shows a flow chart of a method for calculating axial thrust of a closed impeller of a centrifugal compressor according to an embodiment of the invention;

FIG. 2 is a flow chart illustrating another method for calculating axial thrust of a shrouded impeller of a centrifugal compressor according to an embodiment of the invention;

fig. 3 is a schematic diagram illustrating an example of a shrouded impeller configuration provided by an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating another example of a shrouded impeller configuration provided by an embodiment of the present invention;

fig. 5 is a schematic structural diagram illustrating a closed impeller axial thrust calculation device of a centrifugal compressor according to an embodiment of the present invention;

fig. 6 shows a schematic physical structure diagram of a closed impeller axial thrust calculation device of a centrifugal compressor according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The embodiment of the invention provides a method for calculating axial thrust of a closed impeller of a centrifugal compressor, which can improve the accuracy of the axial thrust of the closed impeller of the centrifugal compressor, and as shown in figure 1, the method comprises the following steps:

101. and respectively calculating a first axial thrust of static pressure of gas at the inlet of the impeller to the impeller, a second axial thrust of static pressure of gap gas at the outer side of a wheel cover of the impeller to the impeller, a third axial thrust of gap gas at the outer side of a wheel disc of the impeller to the impeller, and a fourth axial thrust of axial momentum change of gas at the inlet and the outlet of the impeller to the impeller.

In the actual operation process of the closed impeller of the centrifugal compressor, various factors are required to be considered to calculate the axial thrust of the closed impeller of the centrifugal compressor, and in order to realize more comprehensive consideration of the factors, in the embodiment of the invention, the axial thrust of the closed impeller of the centrifugal compressor with higher accuracy can be calculated by combining the influences of the static pressure of the gas at the inlet of the impeller, the static pressure of the gas at the outer side of the wheel cover of the impeller, the gas at the outer side of the wheel disc of the impeller and the axial momentum change of the gas at the inlet and the outlet.

The execution main body of the embodiment of the invention can be a device for calculating the axial thrust of the closed impeller of the centrifugal compressor, when the device receives a corresponding calculation instruction, the device respectively calculates the axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller, the axial thrust of the static pressure of the gas at the outer side of the wheel cover of the impeller to the impeller, the axial thrust of the gas at the outer side of the wheel disc of the impeller, and the axial thrust of the gas at the inlet and the outlet of the impeller to the impeller by combining the four axial thrusts to calculate the axial thrust of the closed impeller of the centrifugal compressor, and the step 102 is specifically executed.

102. And determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust.

For example, the axial thrust of the static pressure of the inlet gas of the impeller to the impeller is F1, the axial thrust of the static pressure of the gap gas outside the impeller cover to the impeller is F2, the axial thrust of the gap gas outside the impeller wheel disk to the impeller is F3, the axial thrust of the change of the axial momentum of the inlet and outlet gas of the impeller to the impeller is F4, and the sum of F1, F2, and F4 is subtracted from F3 to obtain a difference value as the total axial thrust of the impeller, that is, the closed impeller axial thrust of the centrifugal compressor.

The method for calculating the axial thrust of the closed impeller of the centrifugal compressor provided by the embodiment of the invention can consider the influence of multiple aspects on the axial thrust of the impeller, comprehensively calculate the axial thrust of the closed impeller of the centrifugal compressor, has more comprehensive consideration factors, perfects the existing method for calculating the axial thrust, and greatly improves the calculation accuracy.

Further, as a refinement and an extension of the above specific implementation of the embodiment of the present invention, another method for calculating an axial thrust of a shrouded impeller of a centrifugal compressor is provided, as shown in fig. 2, where the method includes:

201. and determining the first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller according to the radial distribution of the static pressure at the inlet of the impeller, the diameter of a front spacer sleeve of the impeller and the axial distribution of the static pressure at the outlet of the impeller.

In the embodiment of the present invention, axial thrust of an impeller by static pressure of impeller inlet gas considers distribution of inlet static pressure along a radial direction and also considers influence of mach number of an impeller machine, and influence of non-uniform distribution of impeller outlet static pressure along an axial direction on closed axial thrust calculation of a centrifugal compressor, and correspondingly, step 201 may specifically include: and calculating the first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller by using a first predetermined formula by taking the minimum diameter of the sealing step of the opening ring of the impeller, the diameter of the front spacer sleeve of the impeller, the maximum static pressure of the impeller in the radial direction, the radial distribution of the static pressure at the inlet of the impeller, the machine Mach number of the impeller and the reference machine Mach number of the impeller as parameters. The static pressure is dimensionless, which is convenient for different inlet pressures to use the same mode.

In an alternative embodiment of the present invention, taking the structure of fig. 3 and 4 as an example, the first predetermined formula may be as follows:

wherein D is_1dMinimum diameter of sealing step for impeller lip ring, D_jIs the diameter of the impeller front spacer, p₀Maximum static pressure, ζ, of the impeller in the radial direction_in(r) is the radial distribution of the static pressure at the inlet of the impeller, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₁The axial thrust of static pressure of gas at the inlet of the impeller to the impeller.

It should be noted that the expression form of the above formula is only an optimal formula given in the embodiment of the present invention, and the axial thrust of the impeller against the static pressure of the impeller inlet gas may also be calculated based on the above formula by performing a modification, such as changing letters in the formula, adding weight coefficients, adding correction coefficients, and the like, which is not limited in the embodiment of the present invention.

202. And determining the second axial thrust of the static pressure of the clearance gas outside the impeller wheel cover to the impeller according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the clearance gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step-type sealing condition.

In the embodiment of the present invention, the axial thrust of the impeller by the static pressure of the gap gas outside the wheel cover of the impeller takes into account the influence of the centrifugal force of the gas outside the wheel cover due to the rotation of the gap gas and the axial thrust of the closed impeller of the centrifugal compressor caused by the non-uniform pressure distribution due to the leakage of the opening ring of the wheel cover, and also takes into account the influence of the stepped seal, and accordingly, step 202 may specifically include: and calculating the second axial thrust of the static pressure of the gap gas outside the impeller cover on the impeller by using a second preset formula and taking the diameter of the impeller, the maximum diameter of the sealing step of the impeller opening ring, the static pressure correction coefficient of the gap inlet outside the impeller cover, the radial variation rule of the static pressure outside the impeller cover, the machine Mach number of the impeller, the reference machine Mach number of the impeller as parameters, the minimum diameter of the sealing step of the impeller opening ring, the radial maximum static pressure of the impeller, the static pressure of the outlet of the impeller and the radial variation rule of the static pressure of the sealing step of the impeller opening ring as parameters. The calculation process takes into account the influence of different machine Mach numbers on the axial thrust of the impeller.

In an alternative embodiment of the present invention, taking the structure of fig. 3 and 4 as an example, the second predetermined formula may be as follows:

wherein D is₂Is the diameter of the impeller, D_1uFor the maximum diameter of the sealing step of the impeller lip ring, p_fs(r) radial distribution of the dimensionless static pressure outside the impeller shroud, β_outFor the static pressure correction coefficient, p, of the entrance to the outboard gap of the wheel cover_fZeta impeller exit static pressure_sout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refMach number of reference machine, D, for impeller_1dFor minimum diameter of sealing step of impeller mouth ring, P₀Maximum static pressure of the impeller in the radial direction, P_1uStatic pressure of the sealing portion of the impeller lip, ζ_sout(r_1u) For the static pressure of sealing steps of the impeller mouth ring to change along the radial direction, F₂The axial thrust of the static pressure of the gap gas outside the impeller cover to the impeller is obtained.

It should be noted that the expression form of the above formula is only an optimal formula given in the embodiment of the present invention, and the axial thrust of the impeller due to the static pressure of the gap gas outside the impeller cover to the impeller may also be calculated based on the above formula by performing a modification, such as changing letters in the formula, increasing a weight coefficient, increasing a correction coefficient, and the like, which is not limited in the embodiment of the present invention.

203. And determining the third axial thrust of the gap gas outside the impeller wheel disc to the impeller according to the centrifugal force generated by the rotation of the gap gas of the gas outside the impeller wheel disc and the pressure distribution caused by the leakage of the wheel cover opening ring.

In the embodiment of the present invention, the axial thrust of the gap gas outside the wheel disc of the impeller to the impeller takes into account the influence of the centrifugal force of the gas outside the wheel cover due to the rotation of the gap gas and the non-uniform pressure distribution caused by the leakage of the opening ring of the wheel cover on the axial thrust of the closed impeller of the centrifugal compressor, and correspondingly, step 203 may specifically include: and calculating a third axial thrust of the clearance gas outside the wheel disc of the impeller to the impeller by using a third preset formula by taking the diameter of the impeller, the diameter of a rear spacer sleeve of the impeller, the static pressure correction coefficient of an inlet of a clearance on the outer side of the wheel disc, the static pressure of an outlet of the impeller, the radial variation rule of the static pressure on the outer side of a wheel cover of the impeller, the machine Mach number of the impeller and the reference machine Mach number of the impeller as parameters.

In an alternative embodiment of the present invention, taking the structure of fig. 3 and 4 as an example, the third predetermined formula may be as follows:

wherein D is₂Is the diameter of the impeller, D_mIs the diameter of the impeller back spacer, gamma_outIs a static pressure correction coefficient, p, of the gap entrance at the outer side of the wheel disc_fZeta impeller exit static pressure_hout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₃The axial thrust of the gap gas at the outer side of the impeller wheel disc to the impeller is obtained.

It should be noted that the expression form of the above formula is only an optimal formula given in the embodiment of the present invention, and the axial thrust of the clearance gas outside the wheel disc of the impeller to the impeller may also be calculated based on the above formula by performing a deformation, such as changing letters in the formula, increasing a weight coefficient, increasing a correction coefficient, and the like, which is not limited in the embodiment of the present invention.

204. And determining the fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller to the impeller according to the axial momentum change of the gas at the inlet and the outlet of the impeller, the flow coefficient of an operating working condition point of the impeller, the flow coefficient of a high-efficiency point of the impeller, the outer diameter of the impeller, the Mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller.

In the embodiment of the present invention, the axial thrust of the impeller due to the change of the axial momentum of the gas at the inlet and the outlet of the impeller takes into account the flow coefficient of the operating condition point of the impeller, the flow coefficient of the high efficiency point of the impeller, the outer diameter of the impeller, the mach number of the impeller, the static pressure at the inlet of the impeller, and the influence of the gas at the inlet of the impeller, and accordingly, step 204 may specifically include: and calculating fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller on the impeller by using a fourth predetermined formula by taking the mass flow of the impeller, the axial speed of the gas at the inlet of the impeller, the axial speed of the gas at the outlet of the impeller, the flow coefficient of a high-efficiency point of a reference impeller, the actual flow coefficient of the impeller, the diameter of the impeller, the reference diameter of the impeller, the machine Mach number of the impeller, the reference machine Mach number of the impeller, the inlet static pressure of the impeller, the inlet reference static pressure of the impeller, the volume entropy index, the reference value of the volume entropy index and the reference value of the axial thrust generated by the axial momentum change.

In an alternative embodiment of the present invention, taking the structure of fig. 3 and 4 as an example, the fourth predetermined formula may be as follows:

wherein Q is_mIs the mass flow rate of the impeller, V_zinIs the axial velocity, V, of the impeller inlet air flow_zoutIs the axial velocity of the impeller outlet flow, phi_1BEPFlow coefficient of impeller high efficiency point, phi_1BEPrefFor reference to the flow coefficient of the high efficiency point of the impeller, phi₁Is the actual flow coefficient of the impeller, D₂Is the diameter of the impeller, D_2refReference diameter of the impeller, Ma machine Mach number of the impeller, Ma_refReference machine Mach number, P, of the impeller_inIs the inlet static pressure, P, of the impeller_inrefIs the inlet reference static pressure of the impeller, Kv is the volume constant entropy index, Kv_refFor reference values of volume constant entropy index, F_4BEPrefIs a reference value of axial thrust generated by the impeller by the change of axial momentum of gas at the inlet and the outlet of the impeller, F₄The axial thrust of the impeller caused by the change of the axial momentum of the gas at the inlet and the outlet of the impeller.

It should be noted that the expression form of the above formula is only an optimal formula given in the embodiment of the present invention, and the axial thrust of the impeller caused by the change of the axial momentum of the gas at the inlet and the outlet of the impeller may also be calculated based on the above formula by performing a deformation, such as changing letters in the formula, increasing a weight coefficient, increasing a correction coefficient, and the like, which is not limited in the embodiment of the present invention.

205. And determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust.

Step 205 may specifically include: and subtracting the first axial thrust from the third axial thrust, subtracting the second axial thrust, subtracting the fourth axial thrust, and taking the difference value obtained finally as the axial total thrust of the impeller.

For example, the total impeller axial thrust, i.e., the closed impeller axial thrust of the centrifugal compressor, may be calculated using the following formula.

F＝F₃-F₁-F₂-F₄

Wherein, F₁Axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller, F₂Axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller, F₃Axial thrust of the static pressure of the gap gas outside the impeller wheel disc to the impeller, F₄The axial thrust generated by the axial momentum change of the gas at the inlet and the outlet of the impeller on the impeller is F, and the F is the total axial thrust of the impeller, namely the axial thrust of the closed impeller of the centrifugal compressor.

It should be noted that the expression form of the above formula is only an optimal formula given in the embodiment of the present invention, and the axial thrust of the closed impeller of the centrifugal compressor may also be calculated by performing a modification based on the above formula, such as changing letters in the formula, increasing a weight coefficient, increasing a correction coefficient, and the like.

Further, in order to facilitate the user to view and manage, after the axial thrust of the closed impeller of the centrifugal compressor is calculated by the method, the axial thrust can be classified according to the numerical values, each grade corresponds to a respective numerical value range, and the calculation results corresponding to the grade style are displayed according to which grade the calculated numerical values belong to. For example, the axial thrust of the closed impeller of the centrifugal compressor can be divided into three levels of danger, medium and safety in advance, and after the axial thrust of the closed impeller of the centrifugal compressor is calculated, if the thrust numerical value is determined to be within the numerical range of the safety level, the thrust numerical value can be displayed by using green characters; if the thrust numerical value is determined to be in the numerical range of the danger level, the thrust numerical value can be displayed by using a red font, and alarm information can be output, wherein the alarm information can be text alarm information, picture alarm information, audio alarm information, video alarm information and the like, so that a user can timely and correspondingly manage, and faults of overhigh temperature of the thrust pad, abrasion of the thrust bearing pad, sealing damage, contact and mutual abrasion of a rotor and a partition plate and the like caused by overlarge axial thrust of the impeller are reduced.

According to the other method for calculating the axial thrust of the closed impeller of the centrifugal compressor, provided by the embodiment of the invention, the influence of the non-uniform distribution of the static pressure at the outlet of the impeller along the axial direction on the calculation of the axial thrust is considered; influence of non-uniform pressure distribution caused by centrifugal force generated by the rotation of the gap gas outside the wheel cover of the wheel disc on the axial thrust of the impeller; influence of actual mouth ring sealing and interstage sealing leakage of the model level on axial thrust of the impeller; the effect of different sealing patterns, such as straight seals and stepped seals, on axial thrust; the influence of different Mach numbers on the axial thrust of the impeller is considered; and the thrust influence generated by the change of the axial momentum of the gas at the inlet and the outlet of the impeller is considered, the consideration factors are more comprehensive, the existing axial thrust calculation method is perfected, and the calculation accuracy is greatly improved.

Further, as a specific implementation of the method shown in fig. 1 and fig. 2, an embodiment of the present invention provides a closed impeller axial thrust calculation apparatus for a centrifugal compressor, as shown in fig. 5, where the apparatus includes: a calculating unit 31 and a determining unit 32.

The calculating unit 31 may be configured to calculate a first axial thrust of the static pressure of the inlet gas of the impeller to the impeller, a second axial thrust of the static pressure of the outer gap gas of the wheel cover of the impeller to the impeller, a third axial thrust of the outer gap gas of the wheel disc of the impeller to the impeller, and a fourth axial thrust of the change of the axial momentum of the inlet and outlet gas of the impeller to the impeller, respectively.

The determining unit 32 may be configured to determine the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust, and the fourth axial thrust.

In a specific application scenario, the calculation unit 31 may be specifically configured to determine a first axial thrust of the static pressure of the impeller inlet to the impeller according to radial distribution of the static pressure of the impeller inlet, a diameter of a spacer sleeve in front of the impeller, and axial distribution of the static pressure of the impeller outlet; determining the second axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the gap gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step-type sealing condition; determining a third axial thrust of the gap gas at the outer side of the impeller wheel disc to the impeller according to the centrifugal force and the pressure distribution; and determining the fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller to the impeller according to the axial momentum change of the gas at the inlet and the outlet of the impeller, the flow coefficient of an operating working condition point of the impeller, the flow coefficient of a high-efficiency point of the impeller, the outer diameter of the impeller, the Mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller.

In a specific application scenario, the calculating unit 31 may be further configured to calculate, by using a first predetermined formula, a first axial thrust of the impeller due to the static pressure of the inlet gas of the impeller to the impeller, using a minimum diameter of the sealing step of the mouth ring of the impeller, a diameter of the front spacer of the impeller, a maximum static pressure of the impeller in the radial direction, a radial distribution of the static pressure of the inlet of the impeller, a machine mach number of the impeller, and a reference machine mach number of the impeller as parameters.

Preferably, the first predetermined formula is

Wherein D is_1dMinimum diameter of sealing step for impeller lip ring, D_jIs the diameter of the impeller front spacer, p₀Maximum static pressure, ζ, of the impeller in the radial direction_in(r) is the radial distribution of the static pressure at the inlet of the impeller, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₁Is the first axial thrust.

In a specific application scenario, the calculating unit 31 may be further configured to calculate a second axial thrust of the static pressure of the gap outside the impeller cover to the impeller by using a second predetermined formula, with the diameter of the impeller, the maximum diameter of the sealing step of the impeller opening ring, the static pressure correction coefficient of the gap entrance outside the impeller cover, the radial variation rule of the static pressure outside the impeller cover, the machine mach number of the impeller, the reference machine mach number of the impeller as a parameter, the minimum diameter of the sealing step of the impeller opening ring, the radial maximum static pressure of the impeller, the static pressure of the impeller exit, and the radial variation rule of the static pressure of the sealing step of the impeller opening ring as parameters.

Preferably, the second predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_1uMaximum diameter of sealing step for impeller lip ring, β_outFor the static pressure correction coefficient, p, of the entrance to the outboard gap of the wheel cover_fZeta impeller exit static pressure_sout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refMach number of reference machine, D, for impeller_1dFor minimum diameter of sealing step of impeller mouth ring, P₀Maximum static pressure, ζ, of the impeller in the radial direction_sout(r_1u) For the static pressure of sealing steps of the impeller mouth ring to change along the radial direction, F₂Is the second axial thrust.

In a specific application scenario, the calculating unit 31 may be further configured to calculate, by using a third predetermined formula, a third axial thrust of the gap gas outside the wheel disc of the impeller to the impeller, using the diameter of the impeller, the diameter of the back spacer of the impeller, the static pressure correction coefficient of the inlet of the clearance at the outer side of the wheel disc, the static pressure at the outlet of the impeller, the radial variation rule of the static pressure at the outer side of the wheel cover of the impeller, the machine mach number of the impeller, and the reference machine mach number of the impeller as parameters.

Preferably, the third predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_mIs the diameter of the impeller back spacer, gamma_outIs a static pressure correction coefficient, p, of the gap entrance at the outer side of the wheel disc_fZeta impeller exit static pressure_hout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₃Is the third axial thrust.

In a specific application scenario, the calculating unit 31 may be further configured to calculate, using a fourth predetermined formula, a fourth axial thrust of the gas inlet/outlet axial momentum change of the impeller to the impeller, using a fourth predetermined formula, as parameters, the mass flow of the impeller, the axial speed of the gas inlet/outlet airflow of the impeller, the axial speed of the gas outlet airflow of the impeller, the flow coefficient of the high-efficiency point of the reference impeller, the actual flow coefficient of the impeller, the diameter of the impeller, the reference diameter of the impeller, the machine mach number of the impeller, the reference machine mach number of the impeller, the inlet static pressure of the impeller, the inlet reference static pressure of the impeller, the volume entropy-fixing index, the reference value of the volume entropy-fixing index, and the reference value of the axial.

Preferably, the fourth predetermined formula is

Wherein Q is_mIs the mass flow rate of the impeller, V_zinIs the axial velocity, V, of the impeller inlet air flow_zoutIs the axial velocity of the impeller outlet flow, phi_1BEPFlow coefficient of impeller high efficiency point, phi_1BEPrefFor reference to the flow coefficient of the high efficiency point of the impeller, phi₁Is the actual flow coefficient of the impeller, D₂Is the diameter of the impeller, D_2refReference diameter of the impeller, Ma machine Mach number of the impeller, Ma_refReference machine Mach number, P, of the impeller_inIs the inlet static pressure, P, of the impeller_inrefIs the inlet reference static pressure of the impeller, Kv is the volume constant entropy index, Kv_refFor volume constant entropy indexReference value, F_4BEPrefIs a reference value of axial thrust generated by the impeller by the change of axial momentum of gas at the inlet and the outlet of the impeller, F₄Is the fourth axial thrust.

In a specific application scenario, the determining unit 32 may be specifically configured to subtract the first axial thrust from the third axial thrust, subtract the second axial thrust, subtract the fourth axial thrust, and obtain a difference value as an impeller axial total thrust.

It should be noted that other corresponding descriptions of the functional units related to the closed impeller axial thrust calculation apparatus of the centrifugal compressor according to the embodiment of the present invention may refer to the corresponding descriptions in fig. 1 and fig. 2, and are not described herein again.

Based on the above-mentioned methods as shown in fig. 1 and fig. 2, correspondingly, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, which when executed by a processor implements the following steps: respectively calculating a first axial thrust of static pressure of air at an inlet of the impeller to the impeller, a second axial thrust of static pressure of clearance air at the outer side of a wheel cover of the impeller to the impeller, a third axial thrust of clearance air at the outer side of a wheel disc of the impeller to the impeller, and a fourth axial thrust of axial momentum change of air at an inlet and an outlet of the impeller to the impeller; and determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust.

Based on the above embodiments of the method shown in fig. 1 and fig. 2 and the apparatus shown in fig. 5, an embodiment of the present invention further provides a physical apparatus for closed impeller axial thrust calculation of a centrifugal compressor, as shown in fig. 6, the apparatus includes: a processor 41, a memory 42, and a computer program stored on the memory 42 and executable on the processor, the processor 41 implementing the following steps when executing the program: respectively calculating a first axial thrust of static pressure of air at an inlet of the impeller to the impeller, a second axial thrust of static pressure of clearance air at the outer side of a wheel cover of the impeller to the impeller, a third axial thrust of clearance air at the outer side of a wheel disc of the impeller to the impeller, and a fourth axial thrust of axial momentum change of air at an inlet and an outlet of the impeller to the impeller; determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust, wherein the device further comprises: a bus 43 configured to couple the processor 41 and the memory 42.

By applying the technical scheme of the invention, the axial thrust of the impeller is calculated by considering the influence of factors such as the form of the impeller, the diameter of the impeller, the rotating speed of the impeller, the flow coefficient of a high-efficiency point of the impeller, working conditions of the impeller, sealing of a mouth ring and an interstage, medium types and the like, so that the consideration is more comprehensive, and the calculation accuracy is higher.

Through the above description of the embodiments, those skilled in the art will clearly understand that the present application can be implemented by hardware, and also by software plus a necessary general hardware platform. Based on such understanding, the technical solution of the present application may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (which may be a CD-ROM, a usb disk, a removable hard disk, etc.), and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the implementation scenarios of the present application.

Those skilled in the art will appreciate that the figures are merely schematic representations of one preferred implementation scenario and that the blocks or flow diagrams in the figures are not necessarily required to practice the present application.

Those skilled in the art will appreciate that the modules in the devices in the implementation scenario may be distributed in the devices in the implementation scenario according to the description of the implementation scenario, or may be located in one or more devices different from the present implementation scenario with corresponding changes. The modules of the implementation scenario may be combined into one module, or may be further split into a plurality of sub-modules.

The above application serial numbers are for description purposes only and do not represent the superiority or inferiority of the implementation scenarios.

The above disclosure is only a few specific implementation scenarios of the present application, but the present application is not limited thereto, and any variations that can be made by those skilled in the art are intended to fall within the scope of the present application.

Claims (20)

1. A method for calculating axial thrust of a closed impeller of a centrifugal compressor is characterized by comprising the following steps:

calculate impeller import gas static pressure respectively to the first axial thrust of impeller, impeller wheel cap outside clearance gas static pressure to the second axial thrust of impeller, impeller rim plate outside clearance gas to the third axial thrust of impeller, impeller import and export the fourth axial thrust of gas axial momentum change to the impeller, specifically include: determining first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller according to the radial distribution of the static pressure at the inlet of the impeller, the diameter of a front spacer sleeve of the impeller and the axial distribution of the static pressure at the outlet of the impeller;

determining the second axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the gap gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step-type sealing condition;

determining a third axial thrust of the gap gas at the outer side of the impeller wheel disc to the impeller according to the centrifugal force and the pressure distribution;

determining fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller on the impeller according to the axial momentum change of the gas at the inlet and the outlet of the impeller, the flow coefficient of an operating working condition point of the impeller, the flow coefficient of a high-efficiency point of the impeller, the outer diameter of the impeller, the Mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller;

determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust, and specifically comprising: and subtracting the first axial thrust from the third axial thrust, subtracting the second axial thrust from the third axial thrust, subtracting the fourth axial thrust from the third axial thrust, and taking the difference value obtained finally as the total axial thrust of the impeller.

2. The method of claim 1, wherein determining a first axial thrust of the impeller from the impeller inlet static pressure in a radial direction, the impeller nose cup diameter, and the impeller exit static pressure in an axial direction comprises:

and calculating the first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller by using a first predetermined formula by taking the minimum diameter of the sealing step of the opening ring of the impeller, the diameter of the front spacer sleeve of the impeller, the maximum static pressure of the impeller in the radial direction, the radial distribution of the static pressure at the inlet of the impeller, the machine Mach number of the impeller and the reference machine Mach number of the impeller as parameters.

3. The method of claim 2, wherein the first predetermined formula is

Wherein D is_1dMinimum diameter of sealing step for impeller lip ring, D_jIs the diameter of the impeller front spacer, p₀Maximum static pressure, ζ, of the impeller in the radial direction_in(r) is the radial distribution of the static pressure at the inlet of the impeller, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₁Is the first axial thrust.

4. The method according to claim 1, wherein the second axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller is determined according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the gap gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step type sealing condition, and the method specifically comprises the following steps:

and calculating the second axial thrust of the static pressure of the gap gas outside the impeller cover on the impeller by using a second preset formula and taking the diameter of the impeller, the maximum diameter of the sealing step of the impeller opening ring, the static pressure correction coefficient of the gap inlet outside the impeller cover, the radial variation rule of the static pressure outside the impeller cover, the machine Mach number of the impeller, the reference machine Mach number of the impeller as parameters, the minimum diameter of the sealing step of the impeller opening ring, the maximum static pressure of the impeller in the radial direction, the static pressure of the impeller outlet and the radial variation rule of the static pressure of the sealing step of the impeller opening ring as parameters.

5. The method of claim 4, wherein the step of determining the target position is performed by a computerThe second predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_1uMaximum diameter of sealing step for impeller lip ring, β_outFor the static pressure correction coefficient, p, of the entrance to the outboard gap of the wheel cover_fZeta impeller exit static pressure_sout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refMach number of reference machine, D, for impeller_1dFor minimum diameter of sealing step of impeller mouth ring, P₀Maximum static pressure, ζ, of the impeller in the radial direction_sout(r_1u) For the static pressure of sealing steps of the impeller mouth ring to change along the radial direction, F₂Is the second axial thrust.

6. The method according to claim 1, wherein determining a third axial thrust of the gap gas outside the wheel disc of the impeller to the impeller based on the centrifugal force and the pressure distribution comprises:

and calculating a third axial thrust of the clearance gas outside the wheel disc of the impeller to the impeller by using a third preset formula by taking the diameter of the impeller, the diameter of a rear spacer sleeve of the impeller, the static pressure correction coefficient of an inlet of a clearance on the outer side of the wheel disc, the static pressure of an outlet of the impeller, the radial variation rule of the static pressure on the outer side of a wheel cover of the impeller, the machine Mach number of the impeller and the reference machine Mach number of the impeller as parameters.

7. The method of claim 6, wherein the third predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_mIs the diameter of the impeller back spacer, gamma_outIs a static pressure correction coefficient, p, of the gap entrance at the outer side of the wheel disc_fZeta impeller exit static pressure_hout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₃Is the third axial thrust.

8. The method according to claim 1, wherein determining a fourth axial thrust of the inlet and outlet gas axial momentum change on the impeller according to the inlet and outlet gas axial momentum change, the flow coefficient of the operating condition point of the impeller, the flow coefficient of the high efficiency point of the impeller, the outer diameter of the impeller, the mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller comprises:

and calculating fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller on the impeller by using a fourth predetermined formula by taking the mass flow of the impeller, the axial speed of the gas at the inlet of the impeller, the axial speed of the gas at the outlet of the impeller, the flow coefficient of a high-efficiency point of a reference impeller, the actual flow coefficient of the impeller, the diameter of the impeller, the reference diameter of the impeller, the machine Mach number of the impeller, the reference machine Mach number of the impeller, the inlet static pressure of the impeller, the inlet reference static pressure of the impeller, the volume entropy index, the reference value of the volume entropy index and the reference value of the axial thrust generated by the axial momentum change.

9. The method of claim 8, wherein the fourth predetermined formula is

Wherein Q is_mIs the mass flow rate of the impeller, V_zinIs the axial velocity, V, of the impeller inlet air flow_zoutIs the axial velocity of the impeller outlet flow, phi_1BEPFlow coefficient of impeller high efficiency point, phi_1BEPrefFor reference to the flow coefficient of the high efficiency point of the impeller, phi₁Is the actual flow coefficient of the impeller, D₂Is the diameter of the impeller, D_2refReference diameter of the impeller, Ma machine Mach number of the impeller, Ma_refReference machine Mach number, P, of the impeller_inIs the inlet static pressure, P, of the impeller_inrefIs the inlet reference static pressure of the impeller, Kv is the volume constant entropy index, Kv_refFor volume constant entropy indexReference value of (F)_4BEPrefIs a reference value of axial thrust generated by the impeller by the change of axial momentum of gas at the inlet and the outlet of the impeller, F₄Is the fourth axial thrust.

10. A centrifugal compressor shrouded impeller axial thrust calculating apparatus comprising:

the calculation unit is used for calculating a first axial thrust of the static pressure of the air at the inlet of the impeller to the impeller, a second axial thrust of the static pressure of the air at the outer side of the wheel cover of the impeller to the impeller, a third axial thrust of the air at the outer side of the wheel disc of the impeller to the impeller, and a fourth axial thrust of the change of the axial momentum of the air at the inlet and the outlet of the impeller to the impeller respectively, and specifically comprises the following steps: determining first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller according to the radial distribution of the static pressure at the inlet of the impeller, the diameter of a front spacer sleeve of the impeller and the axial distribution of the static pressure at the outlet of the impeller;

determining the second axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the gap gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step-type sealing condition;

determining a third axial thrust of the gap gas at the outer side of the impeller wheel disc to the impeller according to the centrifugal force and the pressure distribution;

determining fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller on the impeller according to the axial momentum change of the gas at the inlet and the outlet of the impeller, the flow coefficient of an operating working condition point of the impeller, the flow coefficient of a high-efficiency point of the impeller, the outer diameter of the impeller, the Mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller;

the determining unit is configured to determine an impeller axial total thrust according to the first axial thrust, the second axial thrust, the third axial thrust, and the fourth axial thrust, and specifically includes: and subtracting the first axial thrust from the third axial thrust, subtracting the second axial thrust from the third axial thrust, subtracting the fourth axial thrust from the third axial thrust, and taking the difference value obtained finally as the total axial thrust of the impeller.

11. The apparatus of claim 10,

the calculation unit is specifically configured to calculate a first axial thrust of the static pressure of the inlet gas of the impeller to the impeller by using a first predetermined formula with parameters of a minimum diameter of a sealing step of the impeller mouth ring, a diameter of a front spacer of the impeller, a maximum static pressure of the impeller in the radial direction, radial distribution of static pressure at the inlet of the impeller, a machine mach number of the impeller, and a reference machine mach number of the impeller.

12. The apparatus of claim 11, wherein the first predetermined formula is

Wherein D is_1dMinimum diameter of sealing step for impeller lip ring, D_jIs the diameter of the impeller front spacer, p₀Maximum static pressure, ζ, of the impeller in the radial direction_in(r) is the radial distribution of the static pressure at the inlet of the impeller, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₁Is the first axial thrust.

13. The apparatus of claim 10,

the calculation unit is specifically configured to calculate a second axial thrust of the static pressure of the gap gas outside the impeller cover to the impeller by using a second predetermined formula, with parameters of the diameter of the impeller, the maximum diameter of the seal step of the impeller opening ring, a static pressure correction coefficient of the gap inlet outside the impeller cover, a radial variation rule of the static pressure outside the impeller cover, a machine mach number of the impeller, a reference machine mach number of the impeller, the minimum diameter of the seal step of the impeller opening ring, the radial maximum static pressure of the impeller, an impeller outlet static pressure, and a radial variation rule of the static pressure of the seal step of the impeller opening ring.

14. The apparatus of claim 13, wherein the second predetermined formula is

Wherein D is₂Is the diameter of the impeller, D_1uMaximum diameter of sealing step for impeller lip ring, β_outFor the static pressure correction coefficient, p, of the entrance to the outboard gap of the wheel cover_fZeta impeller exit static pressure_sout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refMach number of reference machine, D, for impeller_1dFor minimum diameter of sealing step of impeller mouth ring, P₀Maximum static pressure, ζ, of the impeller in the radial direction_sout(r_1u) For the static pressure of sealing steps of the impeller mouth ring to change along the radial direction, F₂Is the second axial thrust.

15. The apparatus of claim 10,

the calculation unit is specifically configured to calculate a third axial thrust of the gap gas outside the wheel disc of the impeller to the impeller by using a third predetermined formula with parameters of an impeller diameter, an impeller back spacer diameter, a static pressure correction coefficient of a gap inlet on the outer side of the wheel disc, an impeller outlet static pressure, a radial variation rule of a static pressure on the outer side of a wheel cover of the impeller, a machine mach number of the impeller, and a reference machine mach number of the impeller.

16. The apparatus of claim 15 wherein the third predetermined formula isWherein D is₂Is the diameter of the impeller, D_mIs the diameter of the impeller back spacer, gamma_outIs a static pressure correction coefficient, p, of the gap entrance at the outer side of the wheel disc_fZeta impeller exit static pressure_hout(r) is the radial variation rule of static pressure outside the impeller cover, Ma is the machine Mach number of the impeller, Ma_refReference machine Mach number, F, of the impeller₃Is the third axial thrust.

17. The apparatus of claim 10,

the calculation unit is specifically configured to calculate, using a fourth predetermined formula, a fourth axial thrust of the gas axial momentum change at the inlet and the outlet of the impeller to the impeller by using a fourth predetermined formula, as parameters, the mass flow of the impeller, the axial speed of the gas flow at the inlet of the impeller, the axial speed of the gas flow at the outlet of the impeller, the flow coefficient of the high-efficiency point of the reference impeller, the actual flow coefficient of the impeller, the diameter of the impeller, the reference diameter of the impeller, the machine mach number of the impeller, the reference machine mach number of the impeller, the inlet static pressure of the impeller, the inlet reference static pressure of the impeller, the volume entropy index, the reference value of the volume entropy index, and the reference value of the.

18. The apparatus of claim 17 wherein the fourth predetermined formula is

Wherein Q is_mIs the mass flow rate of the impeller, V_zinIs the axial velocity, V, of the impeller inlet air flow_zoutIs the axial velocity of the impeller outlet flow, phi_1BEPFlow coefficient of impeller high efficiency point, phi_1BEPrefFor reference to the flow coefficient of the high efficiency point of the impeller, phi₁Is the actual flow coefficient of the impeller, D₂Is the diameter of the impeller, D_2refReference diameter of the impeller, Ma machine Mach number of the impeller, Ma_refReference machine Mach number, P, of the impeller_inIs the inlet static pressure, P, of the impeller_inrefIs the inlet reference static pressure of the impeller, Kv is the volume constant entropy index, Kv_refFor reference values of volume constant entropy index, F_4BEPrefIs a reference value of axial thrust generated by the impeller by the change of axial momentum of gas at the inlet and the outlet of the impeller, F₄Is the fourth axial thrust.

19. A computer-readable storage medium, on which a computer program is stored, which program, when executed by a processor, carries out the steps of:

calculate impeller import gas static pressure respectively to the first axial thrust of impeller, impeller wheel cap outside clearance gas static pressure to the second axial thrust of impeller, impeller rim plate outside clearance gas to the third axial thrust of impeller, impeller import and export the fourth axial thrust of gas axial momentum change to the impeller, specifically include: determining first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller according to the radial distribution of the static pressure at the inlet of the impeller, the diameter of a front spacer sleeve of the impeller and the axial distribution of the static pressure at the outlet of the impeller;

determining the second axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the gap gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step-type sealing condition;

determining a third axial thrust of the gap gas at the outer side of the impeller wheel disc to the impeller according to the centrifugal force and the pressure distribution;

determining fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller on the impeller according to the axial momentum change of the gas at the inlet and the outlet of the impeller, the flow coefficient of an operating working condition point of the impeller, the flow coefficient of a high-efficiency point of the impeller, the outer diameter of the impeller, the Mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller;

determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust, and specifically comprising: and subtracting the first axial thrust from the third axial thrust, subtracting the second axial thrust from the third axial thrust, subtracting the fourth axial thrust from the third axial thrust, and taking the difference value obtained finally as the total axial thrust of the impeller.

20. A closed impeller axial thrust calculation device for a centrifugal compressor, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to perform the steps of:

calculate impeller import gas static pressure respectively to the first axial thrust of impeller, impeller wheel cap outside clearance gas static pressure to the second axial thrust of impeller, impeller rim plate outside clearance gas to the third axial thrust of impeller, impeller import and export the fourth axial thrust of gas axial momentum change to the impeller, specifically include: determining first axial thrust of the static pressure of the gas at the inlet of the impeller to the impeller according to the radial distribution of the static pressure at the inlet of the impeller, the diameter of a front spacer sleeve of the impeller and the axial distribution of the static pressure at the outlet of the impeller;

determining the second axial thrust of the static pressure of the gap gas outside the impeller wheel cover to the impeller according to the centrifugal force of the gas outside the impeller wheel cover due to the rotation of the gap gas, the pressure distribution caused by the leakage of the wheel cover opening ring and the step-type sealing condition;

determining a third axial thrust of the gap gas at the outer side of the impeller wheel disc to the impeller according to the centrifugal force and the pressure distribution;

determining fourth axial thrust of the axial momentum change of the gas at the inlet and the outlet of the impeller on the impeller according to the axial momentum change of the gas at the inlet and the outlet of the impeller, the flow coefficient of an operating working condition point of the impeller, the flow coefficient of a high-efficiency point of the impeller, the outer diameter of the impeller, the Mach number of the impeller, the static pressure of the inlet of the impeller and the gas at the inlet of the impeller;

determining the total axial thrust of the impeller according to the first axial thrust, the second axial thrust, the third axial thrust and the fourth axial thrust, and specifically comprising: and subtracting the first axial thrust from the third axial thrust, subtracting the second axial thrust from the third axial thrust, subtracting the fourth axial thrust from the third axial thrust, and taking the difference value obtained finally as the total axial thrust of the impeller.

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