Gas turbine bifurcated exhaust pipe capable of meeting emission requirements of flue gas on two sides

Abstract

The utility model belongs to the technical field of gas turbines, and relates to a bifurcated exhaust pipe of a gas turbine, which meets the emission requirements of smoke on two sides. The forked exhaust pipe of the gas turbine has the advantages of being simple in structure, stable in performance, efficient, environmentally friendly and the like. The bifurcate exhaust pipe can effectively meet the requirement for simultaneous emission of smoke on the two sides, the bifurcate exhaust pipe with the divergence angle smaller than 7 degrees and the smooth streamline face is adopted, exhaust noise, heat loss and emission resistance are reduced, the structural strength, rigidity and heat resistance of the bifurcate exhaust pipe are enhanced, and the overall performance and efficiency of the gas turbine are improved. In addition, in a high-temperature environment, the bifurcated exhaust pipe can still keep a good emission effect and durability.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas turbines and relates to a gas turbine bifurcated exhaust pipe which meets the requirements of smoke emission on both sides. Background Art

[0002] In the prior art, the exhaust passage of the gas turbine output is often collected by a volute, and then exhausted through a radial pipe. Its exhaust structure cannot effectively meet the requirements of simultaneous exhaust of flue gas on both sides; and it is easy to cause problems such as airflow separation, heat energy loss, high noise and poor exhaust in high temperature and high speed environments. Therefore, a new type of gas turbine bifurcated exhaust pipe that meets the requirements of flue gas exhaust on both sides is urgently needed to solve these problems.

[0003] In view of this, the present utility model is proposed. Utility Model Content

[0004] The purpose of the utility model is to overcome the disadvantages of the prior art and provide a gas turbine bifurcated exhaust pipe that meets the smoke emission requirements on both sides.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] The utility model provides a gas turbine bifurcated exhaust pipe that meets the smoke emission requirements on both sides, comprising a bifurcated exhaust pipe, wherein the bifurcated exhaust pipe is provided with a load-bearing casing connected to the gas turbine exhaust port, the load-bearing casing is respectively connected to a left exhaust pipe and a right exhaust pipe with smooth and streamlined pipe surfaces, the left exhaust pipe and the right exhaust pipe are symmetrically arranged, and the equivalent expansion angle range of the left exhaust pipe and the right exhaust pipe is 0-7 degrees;

[0007] The left exhaust pipe and the right exhaust pipe are both provided with a first exhaust port in the vertical direction, and are both provided with a second exhaust port in the horizontal direction for connecting to a waste heat utilization device.

[0008] Specifically, cross sections of the first exhaust port and the second exhaust port are perpendicular to each other.

[0009] Specifically, the center point of each of the second exhaust ports is on the same horizontal line as the center point of the gas turbine exhaust port.

[0010] Specifically, each of the first exhaust ports is provided with an exhaust regulating valve.

[0011] Specifically, the first exhaust port is provided with a first flange, and the second exhaust port is provided with a second flange, and the first flange and the second flange are perpendicular to each other.

[0012] The utility model also provides a design method for a gas turbine bifurcated exhaust pipe that meets the smoke emission requirements on both sides. The specific method is as follows:

[0013] Step 1: According to the actual shape of the gas turbine power turbine, the exhaust flow rate during use, and the utilization of waste heat, a model of the gas turbine bifurcated exhaust pipe is established, that is, the gas turbine bifurcated exhaust pipe is designed as a special-shaped bifurcated exhaust pipe, and the streamline of the pipe surface is ensured to be smooth;

[0014] Step 2: Use the software Fluent to simulate the gas turbine bifurcated exhaust pipe to discharge the flue gas, and adjust the shape of the gas turbine bifurcated exhaust pipe to meet the emission requirements;

[0015] Step 3: Design a first exhaust port and a second exhaust port on the left exhaust pipe and the right exhaust pipe respectively.

[0016] Specifically, in step 2, when simulating smoke emission, multiple key sections with uniformly distributed equivalent lengths are intercepted in the model, and it is ensured that the equivalent expansion angle between every two sections is less than 7 degrees.

[0017] The utility model also provides a method for using a gas turbine bifurcated exhaust pipe that meets the smoke emission requirements on both sides. The specific method of use is as follows:

[0018] The load-bearing casing of the bifurcated exhaust pipe is installed to the exhaust port of the gas turbine. The flue gas enters the bifurcated exhaust pipe through the exhaust port of the gas turbine, and forms two flue gas paths after passing through the left exhaust pipe and the right exhaust pipe respectively. The first flue gas is discharged into the atmosphere from the first exhaust port, and the second flue gas enters the waste heat utilization device from the second exhaust port, thereby realizing the reuse of the waste heat of the flue gas.

[0019] Specifically, the first exhaust port is further provided with an exhaust regulating valve for adjusting the flue gas flow and balancing the exhaust pressure.

[0020] Specifically, the waste heat utilization device includes but is not limited to a heating system and a boiler system.

[0021] Compared with the prior art, the technical solution provided by the utility model includes the following beneficial effects:

[0022] The utility model of the gas turbine bifurcated exhaust pipe has the characteristics of simple structure, stable performance, high efficiency and environmental protection. It can effectively meet the demand for simultaneous emission of flue gas on both sides, and adopts a bifurcated exhaust pipe with a volume expansion angle of less than 7 degrees and a smooth streamlined surface, which reduces exhaust noise, heat energy loss and emission resistance, strengthens the structural strength and rigidity of the bifurcated exhaust pipe, and the smooth streamlined pipe surface improves the overall performance and efficiency of the gas turbine. In addition, in a high temperature environment, the bifurcated exhaust pipe can still maintain good emission effect and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings herein are incorporated into and constitute a part of this specification, and together with the description, are used to explain the principles of the present utility model.

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 This is a front view of a bifurcated exhaust pipe of a gas turbine according to the utility model;

[0026] Figure 2 for Figure 1 A top view of

[0027] Figure 3 for Figure 1 Side view of

[0028] Figure 4 A three-dimensional diagram of the installation structure of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0029] Figure 5 It is a schematic diagram of a key cross section of a bifurcated exhaust pipe of a gas turbine of the utility model;

[0030] Figure 6 It is a schematic diagram of the equivalent expansion angle of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0031] Figure 7 It is the overall flow field streamline distribution diagram of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0032] Figure 8 It is a flow field streamline distribution diagram at the load-bearing casing of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0033] Fig. 9 It is a flow field streamline distribution diagram at the right exhaust pipe of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0034] Fig.10 It is a flow field streamline distribution diagram at the exhaust port of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0035] Fig.11 The Ma distribution diagram of the overall cross-section of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0036] Fig.12 It is the Ma number distribution diagram of the cross section at the exhaust port of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0037] Fig.13 It is the Ma number distribution diagram of the cross section of the exhaust pipe of the bifurcated exhaust pipe of the gas turbine of the utility model;

[0038] Fig.14 This is the Ma distribution diagram of the horizontal cross-section of the bifurcated exhaust pipe of the gas turbine of the utility model with the support plate.

[0039] Among them: 1 is the load-bearing casing; 2 is the left exhaust pipe; 3 is the right exhaust pipe; 4 is the first exhaust port; 5 is the second exhaust port; 6 is the first flange; 7 is the second flange. DETAILED DESCRIPTION

[0040] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the accompanying drawings. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present utility model. Instead, they are only examples consistent with some aspects of the present utility model as detailed in the appended claims.

[0041] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0042] Example 1

[0043] The present embodiment provides a gas turbine bifurcated exhaust pipe that meets the smoke emission requirements on both sides, including a bifurcated exhaust pipe, wherein the bifurcated exhaust pipe is provided with a load-bearing casing 1 connected to the exhaust port of the gas turbine, wherein the load-bearing casing is respectively connected to a left exhaust pipe 2 and a right exhaust pipe 3 with smooth and streamlined pipe surfaces, wherein the left exhaust pipe 2 and the right exhaust pipe 3 are symmetrically arranged, and the equivalent expansion angle range of the left exhaust pipe 2 and the right exhaust pipe 3 is 0-7 degrees, see Figure 1 As shown;

[0044] The left exhaust pipe 2 and the right exhaust pipe 3 are both provided with a first exhaust port 4 in the vertical direction, and are both provided with a second exhaust port 5 in the horizontal direction for connecting to a waste heat utilization device. Figure 2-3 shown.

[0045] Specifically, the cross sections of the first exhaust port 4 and the second exhaust port 5 are perpendicular to each other.

[0046] Specifically, the center point of each of the second exhaust ports 5 is on the same horizontal line as the center point of the gas turbine exhaust port, see Figure 1 shown.

[0047] Specifically, each of the first exhaust ports 4 is provided with an exhaust regulating valve.

[0048] Specifically, the first exhaust port 4 is provided with a first flange 6, and the second exhaust port 5 is provided with a second flange 7. The first flange 6 and the second flange 7 are perpendicular to each other. Figure 1 shown.

[0049] On the other hand, referring to Example 1, the present invention also provides a method for designing a bifurcated exhaust pipe of a gas turbine that meets the smoke emission requirements on both sides. The specific method is as follows:

[0050] According to the actual shape, exhaust flow rate and waste heat utilization of the gas turbine power turbine, it is concluded that the bifurcated exhaust pipe does not have the geometric characteristics of a spiral body, and the exhaust characteristics of the gas turbine power turbine need to be exhausted to both sides to achieve multiple working modes. The exhaust pipe needs to form a bifurcated pipe structure to meet the emission requirements; according to the structural characteristics that the gas turbine power turbine is connected to the reducer and the axial distance between the two is relatively close, the bifurcated exhaust pipe is independently designed by aerodynamic design, and the model of the bifurcated exhaust pipe is established; see Figure 4 As shown;

[0051] Table 1 Input conditions for power turbine aerodynamic design

[0052] Technical parameter name Rated state parameters unit Gas physical flow 11.0 kg / s Power turbine physical speed 12900 rpm Power turbine inlet total temperature 855.2 K Power turbine inlet total pressure 167.2 kPa Power turbine exhaust total temperature 766.6 K Power turbine exhaust total pressure 103.3 kPa

[0053] According to the performance requirements and thermodynamic parameter decomposition of the power turbine in Table 1, the basic performance parameters of the design point of the bifurcated exhaust pipe (sea level standard atmospheric conditions, 288.15K, 101325Pa) are obtained as follows: total pressure recovery coefficient of the bifurcated exhaust pipe: ≥0.970;

[0054] During the technical index decomposition process, the total pressure recovery coefficient of the bifurcated exhaust pipe is set to 0.970 to ensure that the gas turbine bifurcated exhaust pipe has a differential pressure of 2000Pa when used in non-electric air conditioners (such as lithium bromide absorption hot and cold water units); in addition to controlling the exhaust speed of the power turbine, it is also necessary to ensure that the streamline of the pipeline profile is smooth and the equivalent expansion angle of the bifurcated exhaust pipe is not too large to prevent losses caused by airflow separation; therefore, each exhaust pipe is designed with 5 key sections (A, B, C, D, E) with uniform equivalent lengths. Figure 5 As shown, the equivalent expansion angle between every two sections is guaranteed to be in the range of 0-7 degrees; see Figure 6 As shown, the equivalent expansion angle range is between 2.8 and 3.8;

[0055] In order to obtain the total pressure loss of the designed bifurcated exhaust pipe, the bifurcated exhaust pipe was numerically simulated; the software used was Fluent, the working fluid was gas, the k-ε turbulence model was selected, and the ICEM was used to divide the grid. The total number of generated grids was 1.78 million, and the wall Yplus (wall Reynolds number) was about 5 (the viscous bottom layer yPlus <5, the fluid is mainly viscous effect), which met the requirements of the turbulence model used in the calculation;

[0056] First, the state of the gas turbine power turbine system only generating electricity was calculated. The boundary conditions of the bifurcated exhaust pipe at this time were: inlet total temperature 774K, total pressure 106500Pa; outlet static pressure, adjust the outlet static pressure (about 101000Pa) to make the flow rate reach 11.9kg / s; the pipes leading to the second exhaust port 5 on both sides were closed and set as wall surfaces like other pipe walls. The obtained flow field streamline distribution diagram is shown in Figure 1. Figure 7-10 As shown;

[0057] The three sections of the inlet section, middle section and outlet section in the pipeline were respectively cut, and the total pressures were: 106424Pa, 106114Pa, 103784Pa; Ma (Mach number) were: 0.241, 0.138, 0.189; total pressure loss: 2716Pa; the total pressure recovery coefficient of the bifurcated exhaust pipe at this time was obtained: 0.9745, which was greater than the design basic performance parameter 0.970 and met the design requirements; the total pressure loss was mainly at the 90-degree turning point of the exhaust to the first exhaust port 4. The design here is conducive to the airflow to the second exhaust port 5 on both sides of the bifurcated exhaust pipe for use by the generator set;

[0058] The calculated Ma distribution of the bifurcated exhaust pipe cross section can be found in Figure 11-13 As shown in the figure, by comparison, it can be found that the maximum Ma position of the Ma number distribution diagram of the horizontal cross-section of the bifurcated exhaust pipe designed occurs near the hub at the bifurcation point, while the calculation here actually occurs near the casing and the maximum Ma value is higher than the design value. This is because the Ma number was calculated without a support plate (the support plate is located at the position of the power turbine exhaust port and is used to adjust the pressure at the power turbine exhaust port), and the pressure distribution is not set at the inlet of the bifurcated exhaust pipe model; in actual use, 6 evenly distributed support plates will be placed at the power turbine exhaust port. After the software is set in this way, see Fig.14 As shown, the position of the maximum Ma number is consistent with the design, and the maximum Ma value is reduced.

[0059] Therefore, the designed bifurcated exhaust pipe flow channel structure can provide aerodynamic structural geometry for the structural design of the power turbine transmission system; moreover, the shape of the bifurcated exhaust pipe designed in this way enhances its structural strength and rigidity, and the smooth and streamlined pipe surface improves the overall performance and efficiency of the gas turbine.

[0060] During actual use, the bifurcated exhaust pipe of the utility model can still maintain a good emission effect after long-term emission of high-temperature exhaust gas from the gas turbine power turbine, and can meet the long-term use of heating systems, boiler systems, non-electric air-conditioning systems, etc., thereby improving the utilization rate of waste heat in the exhaust gas.

[0061] On the other hand, referring to Example 1, the utility model also provides a method for using a gas turbine bifurcated exhaust pipe that meets the smoke emission requirements on both sides. The specific method of use is as follows:

[0062] The load-bearing casing 1 of the bifurcated exhaust pipe is installed to the exhaust port of the gas turbine. The flue gas enters the bifurcated exhaust pipe through the exhaust port of the gas turbine, and forms two flue gas paths after passing through the left exhaust pipe 2 and the right exhaust pipe 3 respectively. The first flue gas is discharged into the atmosphere from the first exhaust port 4, and the second flue gas enters the waste heat utilization device from the second exhaust port 5, thereby realizing the reuse of the waste heat of the flue gas.

[0063] Specifically, the first exhaust port 4 is also provided with an exhaust regulating valve for adjusting the flue gas flow and balancing the exhaust pressure.

[0064] Specifically, the waste heat utilization device includes but is not limited to a heating system and a boiler system.

[0065] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0066] It should be understood that the present invention is not limited to the above-described contents, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A gas turbine bifurcated exhaust pipe that meets the smoke emission requirements on both sides, characterized in that: The invention comprises a bifurcated exhaust pipe, wherein the bifurcated exhaust pipe is provided with a load-bearing casing (1) connected to an exhaust port of a gas turbine, the load-bearing casing (1) is respectively connected to a left exhaust pipe (2) and a right exhaust pipe (3) with smooth and streamlined pipe surfaces, the left exhaust pipe (2) and the right exhaust pipe (3) are symmetrically arranged, and the equivalent expansion angle range of the left exhaust pipe (2) and the right exhaust pipe (3) is 0-7 degrees; The left exhaust pipe (2) and the right exhaust pipe (3) are both provided with a first exhaust port (4) in the vertical direction, and are both provided with a second exhaust port (5) in the horizontal direction for connecting to a waste heat utilization device.

2. The gas turbine bifurcated exhaust pipe according to claim 1, characterized in that: The cross sections of the first exhaust port (4) and the second exhaust port (5) are perpendicular to each other.

3. The gas turbine bifurcated exhaust pipe according to claim 1, characterized in that: The center point of each of the second exhaust ports (5) is on the same horizontal line as the center point of the gas turbine exhaust port.

4. The gas turbine bifurcated exhaust pipe according to claim 1, characterized in that: Each of the first exhaust ports (4) is provided with an exhaust regulating valve.

5. The gas turbine bifurcated exhaust pipe according to claim 1, characterized in that: The first exhaust port (4) is provided with a first flange (6), and the second exhaust port (5) is provided with a second flange (7), and the first flange (6) and the second flange (7) are perpendicular to each other.

6. The gas turbine bifurcated exhaust pipe according to claim 1, characterized in that: The waste heat utilization device includes but is not limited to a heating system and a boiler system.

Images