1. A method for calculating the oil leakage amount of a broken gas turbine pipeline is characterized by comprising the following steps:

step one, constructing a gas turbine pipeline fracture oil leakage model;

acquiring a first balance equation of the flow of fuel flowing into a pipeline of the gas turbine and the flow of fuel flowing out of the pipeline of the gas turbine, and acquiring a second balance equation of the flow of fuel in the combustion chamber and the flow of fuel flowing into the combustion chamber from each nozzle;

acquiring inlet fuel pressure of a gas turbine pipeline and outlet fuel pressure of a fuel branch pipe at a fracture position, and acquiring a third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of each nozzle;

and step four, calculating the leakage amount of the fuel according to the first balance equation, the second balance equation and the third balance equation.

2. The method for calculating the amount of oil leakage caused by the fracture of the gas turbine pipeline according to claim 1, wherein in the first step, the constructing the model of the oil leakage caused by the fracture of the gas turbine pipeline comprises:

obtaining model simplification principles, comprising:

assuming that the nozzle of the fuel branch pipe at the fracture position does not work any more, namely the flow rate of the nozzle is 0, the fuel flowing into the fuel branch pipe leaks at the fracture position;

in the working process of the gas turbine, supposing that the fuel branch pipe fracture fault can not cause the combustion efficiency of the combustion chamber to be changed remarkably, when the fuel branch pipe fractures, in order to achieve a certain preset working state, the flow of the fuel entering the flame tube is the theoretical oil supply quantity Q of the state₀The fuel flow supplied to the oil inlet pipe by the actual oil pump is increased to Q due to the influence of fuel leakage caused by the fracture of the fuel branch pipe_0d；

And constructing a gas turbine pipeline fracture and oil leakage model based on the model simplification principle.

3. The method for calculating the amount of fuel leakage due to the broken gas turbine pipeline as claimed in claim 2, wherein in the second step, the obtaining of the first balance equation of the fuel flow into the gas turbine pipeline and the fuel flow out of the gas turbine pipeline comprises:

Q_0d＝Q₁+Q₂...+Q_i-1+Q_i+Q_i+1...+Q_n。

wherein Q is_iIs the leakage of fuel, Q₁、Q₂、…Q_i-1、Q_i+1…, Qn are the fuel flows from the remaining nozzles into the combustion chamber.

4. The method for calculating the amount of fuel leakage due to pipeline breakage of a gas turbine as claimed in claim 3, wherein in the second step, the second equation for obtaining the fuel supply to the combustion chamber and the fuel flow from each nozzle to the combustion chamber comprises:

Q₀＝Q₁+Q₂...+Q_i-1+Q_i+1...+Q_n。

wherein Q is_iIs the leakage of fuel, Q₁、Q₂、…Q_i-1、Q_i+1…, Qn are the fuel flows from the remaining nozzles into the combustion chamber.

5. The method for calculating the amount of oil leakage caused by the breakage of the gas turbine pipeline according to claim 4, wherein in the third step, the obtaining of the third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the fuel branch pipe at the breakage position comprises:

wherein, P₀Is the pressure of the inlet fuel, ρ is the density of the fuel, v₀Is the characteristic velocity, P, of the inlet fuel₁₃Is the pressure outside the combustion chamber casing, m_jThe number of on-way lines, k, contained in the section of line_jFor the number of local resistance lines, λ, contained in the section_jIs the on-way drag coefficient, L, on the jth on-way pipeline_jIs the characteristic length on the jth on-way line, d_jIs the characteristic diameter, V, of the jth on-way line_jIs the characteristic speed, ζ, of the jth on-way line_jIs the local resistance coefficient on the jth local resistance pipeline, v_jIs the characteristic velocity, v, of the jth local resistance line_iIs the flow rate of the fuel.

6. The method for calculating the oil leakage at the fracture of the pipeline of the gas turbine as claimed in claim 5, wherein the local resistance pipeline of the fuel branch pipe at the fracture position comprises a sudden expansion section, a sudden contraction section, a bent pipe section, a three-way pipe and a local resistance section generated by the fracture.

7. The method for calculating the oil leakage at the fracture of the pipeline of the gas turbine as claimed in claim 6, wherein the local resistance section generated by the fracture obtains the local resistance coefficient according to the suction fluid which is circularly turned by 180 degrees in space.

8. The method for calculating the amount of fuel leakage due to breakage of a gas turbine pipeline according to claim 5, wherein in the third step, the obtaining of the third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of each nozzle comprises:

the third equilibrium equation for the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the 1 st nozzle is:

the third equation of equilibrium between the inlet fuel pressure of the gas turbine piping and the outlet fuel pressure of the 2 nd nozzle is:

the third equilibrium equation for the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the nth nozzle is as follows:

wherein, P₀Is the pressure of the inlet fuel, ρ is the density of the fuel,v₀is the characteristic velocity, P, of the inlet fuel₃Is the pressure of the combustion chamber, m₁...m_nTo correspond to the number of on-way lines, k, contained in the nozzle line₁...k_nTo correspond to the number of local resistance lines, lambda, contained in the nozzle line_jIs the on-way drag coefficient, L, on the jth on-way pipeline_jIs the characteristic length on the jth on-way line, d_jIs the characteristic diameter, V, of the jth on-way line_jIs the characteristic speed, ζ, of the jth on-way line_jIs the local resistance coefficient on the jth local resistance pipeline, v_jCharacteristic speed, f, of the jth local resistance line₁(Q₁)…f_n(Q_n) Is the flow resistance of the corresponding nozzle at the corresponding fuel flow rate.

9. The method of claim 8, wherein the local resistance line of each nozzle fuel line comprises a sudden expansion section, a sudden contraction section, a bent pipe section and a tee pipe.

Background

The fuel oil branch pipe of the gas turbine can be broken in the working process, and fuel oil leakage brings great risk to the use of the gas turbine.

In the prior art, the fuel oil leakage is evaluated by numerical simulation, on one hand, the internal structure of the nozzle is complex, the simulation technology difficulty of the flow resistance of the nozzle in different states is high, and the structure of the nozzle needs to be simplified corresponding to each working state; on the other hand, the debugging difficulty of numerical simulation modeling solving is high, and due to the large number of grids of numerical simulation modeling, the requirement on hardware resources is high, modeling needs to be carried out again for different gas turbine states and different fracture gaps, repeated iterative calculation is needed, the workload is high, the calculation period is long, and the time cost is high; compared with the whole fuel main pipe, the fracture gap is small in size, the number of grids in the whole calculation domain is large, the calculation period is long, and the calculation efficiency is low.

Accordingly, a technical solution is desired to overcome or at least alleviate at least one of the above-mentioned drawbacks of the prior art.

Disclosure of Invention

The application aims to provide a method for calculating the oil leakage caused by the broken pipeline of the gas turbine, so as to solve at least one problem in the prior art.

The technical scheme of the application is as follows:

a method for calculating the oil leakage of a broken gas turbine pipeline comprises the following steps:

step one, constructing a gas turbine pipeline fracture oil leakage model;

acquiring a first balance equation of the flow of fuel flowing into a pipeline of the gas turbine and the flow of fuel flowing out of the pipeline of the gas turbine, and acquiring a second balance equation of the flow of fuel in the combustion chamber and the flow of fuel flowing into the combustion chamber from each nozzle;

acquiring inlet fuel pressure of a gas turbine pipeline and outlet fuel pressure of a fuel branch pipe at a fracture position, and acquiring a third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of each nozzle;

and step four, calculating the leakage amount of the fuel according to the first balance equation, the second balance equation and the third balance equation.

Optionally, in the first step, the constructing a gas turbine pipeline fracture oil leakage model includes:

obtaining model simplification principles, comprising:

assuming that the nozzle of the fuel branch pipe at the fracture position does not work any more, namely the flow rate of the nozzle is 0, the fuel flowing into the fuel branch pipe leaks at the fracture position;

in the working process of the gas turbine, supposing that the fuel branch pipe fracture fault can not cause the combustion efficiency of the combustion chamber to be changed remarkably, when the fuel branch pipe fractures, in order to achieve a certain preset working state, the flow of the fuel entering the flame tube is the theoretical oil supply quantity Q of the state₀The fuel flow supplied to the oil inlet pipe by the actual oil pump is increased to Q due to the influence of fuel leakage caused by the fracture of the fuel branch pipe_0d；

And constructing a gas turbine pipeline fracture and oil leakage model based on the model simplification principle.

Optionally, in step two, the obtaining a first balance equation of the fuel flow into the gas turbine pipeline and the fuel flow out of the gas turbine pipeline includes:

Q_0d＝Q₁+Q₂...+Q_i-1+Q_i+Q_i+1...+Q_n。

wherein Q is_iIs the leakage of fuel, Q₁、Q₂、…Q_i-1、Q_i+1…, Qn are eachThe fuel flow from each of the remaining nozzles into the combustion chamber.

Optionally, in step two, the second equation for obtaining the oil supply amount of the combustion chamber and the fuel flow amount flowing into the combustion chamber from each nozzle includes:

Q₀＝Q₁+Q₂...+Q_i-1+Q_i+1...+Q_n。

wherein Q is_iIs the leakage of fuel, Q₁、Q₂、…Q_i-1、Q_i+1…, Qn are the fuel flows from the remaining nozzles into the combustion chamber.

Optionally, in step three, the obtaining a third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the fuel branch pipe at the fracture position includes:

wherein, P₀Is the pressure of the inlet fuel, ρ is the density of the fuel, v₀Is the characteristic velocity, P, of the inlet fuel₁₃Is the pressure outside the combustion chamber casing, m_jThe number of on-way lines, k, contained in the section of line_jFor the number of local resistance lines, λ, contained in the section_jIs the on-way drag coefficient, L, on the jth on-way pipeline_jIs the characteristic length on the jth on-way line, d_jIs the characteristic diameter, V, of the jth on-way line_jIs the characteristic speed, ζ, of the jth on-way line_jIs the local resistance coefficient on the jth local resistance pipeline, v_jIs the characteristic velocity, v, of the jth local resistance line_iIs the flow rate of the fuel.

Optionally, the local resistance pipeline of the fuel branch pipe at the fracture position comprises a sudden expansion section, a sudden contraction section, a bent pipe section, a three-way pipe and a local resistance section generated by the fracture.

Optionally, the local resistance section generated by the fracture obtains the local resistance coefficient according to the sucked fluid of which the space is circularly turned for 180 degrees.

Optionally, in step three, the obtaining a third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of each nozzle includes:

the third equilibrium equation for the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the 1 st nozzle is:

the third equation of equilibrium between the inlet fuel pressure of the gas turbine piping and the outlet fuel pressure of the 2 nd nozzle is:

the third equilibrium equation for the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the nth nozzle is as follows:

wherein, P₀Is the pressure of the inlet fuel, ρ is the density of the fuel, v₀Is the characteristic velocity, P, of the inlet fuel₃Is the pressure of the combustion chamber, m₁...m_nTo correspond to the number of on-way lines, k, contained in the nozzle line₁...k_nTo correspond to the number of local resistance lines, lambda, contained in the nozzle line_jIs the on-way drag coefficient, L, on the jth on-way pipeline_jIs the characteristic length on the jth on-way line, d_jIs the characteristic diameter, V, of the jth on-way line_jIs the characteristic speed, ζ, of the jth on-way line_jIs the local resistance coefficient on the jth local resistance pipeline, v_jCharacteristic speed, f, of the jth local resistance line₁(Q₁)…f_n(Q_n) Is the flow resistance of the corresponding nozzle at the corresponding fuel flow rate.

Optionally, the local resistance line of each nozzle fuel line comprises a sudden expansion section, a sudden contraction section, a bend section and a tee.

The invention has at least the following beneficial technical effects:

according to the method for calculating the fuel leakage amount of the gas turbine pipeline in the fracture mode, the fuel leakage model of the gas turbine pipeline in the fracture mode is established, the fuel leakage amount is calculated through the balance equation of the fuel flow and the fuel pressure of the gas turbine pipeline, and the calculation efficiency and the calculation precision are improved.

Drawings

FIG. 1 is a schematic illustration of a gas turbine pipeline configuration according to an embodiment of the present application;

FIG. 2 is a schematic illustration of fuel line flow after a fuel line break in accordance with an embodiment of the present application;

FIG. 3 is a schematic view of a 180 degree circular turn in a fracture cross-section space according to an embodiment of the present application;

FIG. 4 is a side view of FIG. 3;

fig. 5 is a fuel injection nozzle flow characteristic curve according to an embodiment of the present application.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are a subset of the embodiments in the present application and not all embodiments in the present application. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application and should not be construed as limiting the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. Embodiments of the present application will be described in detail below with reference to the accompanying drawings.

In the description of the present application, it is to be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present application and for simplifying the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore should not be construed as limiting the scope of the present application.

The present application is described in further detail below with reference to fig. 1 to 5.

The application provides a method for calculating the oil leakage of a broken gas turbine pipeline, which comprises the following steps:

step one, constructing a gas turbine pipeline fracture oil leakage model;

acquiring a first balance equation of the flow of fuel flowing into a pipeline of the gas turbine and the flow of fuel flowing out of the pipeline of the gas turbine, and acquiring a second balance equation of the flow of fuel in the combustion chamber and the flow of fuel flowing into the combustion chamber from each nozzle;

acquiring inlet fuel pressure of a gas turbine pipeline and outlet fuel pressure of a fuel branch pipe at a fracture position, and acquiring a third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of each nozzle;

and step four, calculating the leakage amount of the fuel according to the first balance equation, the second balance equation and the third balance equation.

As shown in FIG. 1, the gas turbine pipeline is a fuel manifold with n nozzles, the fuel manifold is arranged outside a combustor casing, wherein, if a fuel branch pipe at the ith nozzle is broken, a part of fuel is jetted from the nozzle to a combustor, and the pressure of the combustor is P₃Simultaneously, the rest of fuel leaks to the outer side of the combustion chamber casing from the fracture, and the pressure of the outer side of the combustion chamber casing is P₁₃。

The utility model provides a gas turbine pipeline fracture oil leakage quantity calculation method considers that the actual fuel oil main pipe that takes the nozzle of engineering carries out certain simplification, and the model simplification principle is as follows:

(1) assuming that the nozzle of the fuel branch pipe at the fracture position does not work any more, namely the flow rate of the nozzle is 0, the fuel flowing into the fuel branch pipe leaks at the fracture position;

(2) in the working process of the gas turbine, supposing that the fuel branch pipe fracture fault can not cause the combustion efficiency of the combustion chamber to be changed remarkably, when the fuel branch pipe fractures, in order to achieve a certain preset working state, the flow of the fuel entering the flame tube is the theoretical oil supply quantity Q of the state₀The fuel flow supplied to the oil inlet pipe by the actual oil pump is increased to Q due to the influence of fuel leakage caused by the fracture of the fuel branch pipe_0d；

And (2) constructing a gas turbine pipeline fracture and oil leakage model based on the model simplification principle, wherein the process that fuel oil enters from an oil inlet pipe, flows out from a nozzle and leaks from a fracture in the graph 1 is simplified into the process that the fuel oil flows through a pipe network, the whole pipe network can be regarded as a branch pipeline, the fuel oil leaks from one branch pipeline, and the other branch pipeline can be regarded as a parallel pipeline consisting of the rest n-1 pipelines.

In the method for calculating the amount of fuel leakage due to the broken gas turbine pipeline, in the second step, a first equilibrium equation of the flow rate of fuel flowing into the gas turbine pipeline and the flow rate of fuel flowing out of the gas turbine pipeline is obtained, and a second equilibrium equation of the flow rate of fuel flowing into the combustion chamber from each nozzle and the flow rate of fuel flowing into the combustion chamber from each nozzle comprises the following steps:

suppose the fuel leakage is Q_iThe fuel flow rate from the other nozzles to the combustion chamber is Q₁、Q₂、…Q_i-1、Q_i+1…, Qn, the flow of fluid into the node is equal to the flow of fluid out of the node according to the characteristics of the branch lines, which can result in equation (1), and the total flow into the parallel lines is equal to the sum of the flows of the parallel branches according to the characteristics of the parallel lines, which can result in equation (2):

Q_0d＝Q₁+Q₂...+Q_i-1+Q_i+Q_i+1...+Q_n (1)

Q₀＝Q₁+Q₂...+Q_i-1+Q_i+1...+Q_n (2)

in the third step, the third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the fuel branch pipe at the fracture position and the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of each nozzle is obtained and includes:

neglecting the influence of height, the fuel pipeline of the broken branch corresponding to the ith spray pipe from the inlet of the oil inlet pipe to the fuel leakage outlet satisfies the following relational expression:

wherein, P₀Is the pressure of the inlet fuel, ρ is the density of the fuel, v₀Is the characteristic velocity, P, of the inlet fuel₁₃Is the pressure outside the combustion chamber casing, m_jThe number of on-way lines, k, contained in the section of line_jFor the number of local resistance lines, λ, contained in the section_jIs the on-way drag coefficient, L, on the jth on-way pipeline_jIs the characteristic length on the jth on-way line, d_jIs the characteristic diameter, V, of the jth on-way line_jIs the characteristic speed, ζ, of the jth on-way line_jIs the local resistance coefficient on the jth local resistance pipeline, v_jIs the characteristic velocity, v, of the jth local resistance line_iIs the flow rate of the fuel.

In this embodiment, the local resistance pipeline of the fuel branch pipe at the fracture position includes a sudden expansion section, a sudden contraction section, a bent pipe section, a three-way pipe, and a local resistance section generated by the fracture. Wherein the local resistance section generated by the fracture obtains the local resistance coefficient according to the sucked fluid which is circularly turned for 180 degrees in space, as shown in figures 3-4.

For the 1 st pipeline fuel flowing from the oil inlet pipe to the nozzle, the third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the 1 st nozzle is as follows:

for the 2 nd pipeline fuel flowing from the oil inlet pipe to the nozzle, the third equilibrium equation of the inlet fuel pressure of the gas turbine pipeline and the outlet fuel pressure of the 2 nd nozzle is as follows:

for the nth pipeline fuel flowing from the fuel inlet pipe until the nozzle flows out, the third equilibrium equation of the inlet fuel pressure of the pipeline of the gas turbine and the outlet fuel pressure of the nth nozzle is as follows:

wherein, P₀Is the pressure of the inlet fuel, ρ is the density of the fuel, v₀Is the characteristic velocity, P, of the inlet fuel₃Is the pressure of the combustion chamber, m₁...m_nTo correspond to the number of on-way lines, k, contained in the nozzle line₁...k_nTo correspond to the number of local resistance lines, lambda, contained in the nozzle line_jIs the on-way drag coefficient, L, on the jth on-way pipeline_jIs the characteristic length on the jth on-way line, d_jIs the characteristic diameter, V, of the jth on-way line_jIs the characteristic speed, ζ, of the jth on-way line_jIs the local resistance coefficient on the jth local resistance pipeline, v_jCharacteristic speed, f, of the jth local resistance line₁(Q₁)…f_n(Q_n) Is the flow resistance of the corresponding nozzle at the corresponding fuel flow rate.

In this embodiment, the local resistance pipeline of each nozzle fuel pipeline includes a sudden expansion section, a sudden contraction section, a bent pipe section and a three-way pipe.

The relationship of flow resistance to flow for a nozzle is determined experimentally, i.e. f₁、f₂、…、f_nThe flow resistance versus flow rate curve of (a) is shown in fig. 5.

Finally, simultaneously solving a nonlinear equation set according to equations (1) - (n +2), and obtaining the leakage quantity Q of the fuel oil_iAnd the flow distribution Q of the fuel₁、Q₂、…Q_i-1、Q_i+1…, Qn. In addition, the flow resistance of each on-way and local resistance element is calculated according to the flow distribution by the formula (3), and finally the pressure at the position of the oil inlet pipe is inversely calculated. And further evaluating the risk of the fuel leakage on the use of the gas turbine according to the fuel leakage amount and the inlet pressure.

According to the method for calculating the fuel leakage amount of the gas turbine pipeline fracture, the whole process that fuel is sprayed out from an oil inlet pipe to a nozzle and leaks from a fracture is divided into the process that fuel flows through an on-way component and a local resistance component, a mathematical calculation model of fuel sub-pipe fracture is established according to a calculation method of pipe network flow resistance and flow distribution, the fuel leakage amount is obtained through a numerical analysis method, the mathematical model can be used for rapidly solving the fuel leakage amount under different gas turbine working states and different fracture gaps, and the calculation efficiency is high. The application solves the following problems that the prior art cannot complete: the influence of the difference of different nozzles on the oil leakage amount is evaluated; the influence of the amplification type nozzle on the oil leakage amount is evaluated; the calculation efficiency and the calculation precision are improved.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.