High-precision checking device and method for temperature field and flow field in gas turbine box

Abstract

The invention relates to a high-precision checking device and method for a temperature field and a flow field in a gas turbine cartridge, a physical model for ejection cooling checking of the gas turbine cartridge is adopted, and the physical model comprises a gas turbine body, an exhaust volute, an ejector and the cartridge, the exhaust volute and the ejector are matched with each other to form an ejection structure, negative pressure is generated, and cooling air completing heat exchange in the box body is sucked into the exhaust pipe in an entrainment mode. The outlet of the exhaust inner reducer pipe and the outlet of the ejector are connected with the inlet of the exhaust pipe, and the inlet of the ejector is connected with the box body, so that the flow condition under the integral matching of the volute, the reducer pipe and the ejector can be accurately simulated. The method for checking the temperature field and the flow field of the box-packed body based on the injection effect according to injection cooling flow characteristics, a physical model for accurate numerical simulation and a calculation model can make up for the defects of an injection test means and guide the design and optimization work of an ejector.

Description

Technical Field

[0001] The invention relates to a marine gas turbine generator set, in particular to a high-precision calibration device and method for temperature field and flow field inside a gas turbine casing. Background Art

[0002] During the operation of the gas turbine, a large amount of heat is radiated through the surface of the body, and the surface of the body needs to be cooled by cooling air. The gas turbine casing usually adopts induced cooling, which takes advantage of its own large exhaust flow rate and high flow velocity, and cooperates with the special structure of the casing ejector to continuously draw cooling air into the casing, and discharge it with the fuel gas after heat dissipation. Unlike the diesel generator casing, the gas turbine casing is open-type cooled, with a large induced flow rate requirement, a complex ejector structure, and no forced heat exchange device is required. At present, the calculation method for the temperature field verification of the diesel generator casing has been verified in a large number of engineering applications, while the gas turbine induced cooling verification method is less used, and the induced flow field verification of the indirect-cooled gas turbine casing is even more limited. Summary of the invention

[0003] The present invention aims to propose a high-precision calibration device for the temperature field and flow field inside the gas turbine casing, and according to the characteristics of the ejection cooling flow, the physical model and the calculation model of the accurate numerical simulation, a method for calibrating the temperature field and flow field of the casing based on the ejection effect is proposed to make up for the shortcomings of the ejection test means and guide the ejector design and optimization work.

[0004] To achieve the above-mentioned purpose, the technical solution of the present invention is: a high-precision calibration device for the temperature field and flow field inside a gas turbine casing, which adopts a physical model for the gas turbine casing ejection cooling calibration, and the physical model includes a gas turbine body, an exhaust volute, an ejector, and a casing. The gas turbine body is composed of a global structured grid, and the exhaust volute and the ejector cooperate with each other to form an ejection structure to generate negative pressure, and the cooling air that completes the heat exchange in the casing is sucked into the exhaust pipe; the outlet of the exhaust reducer and the ejector outlet are connected to the exhaust pipe inlet, and the ejector inlet is connected to the casing, which is used to accurately simulate the flow conditions under the overall cooperation of the volute, the reducer and the ejector.

[0005] A high-precision calibration method for the temperature field and flow field inside a gas turbine casing based on the ejection effect is adopted. A high-precision calibration device for the temperature field and flow field inside the gas turbine casing is adopted. Firstly, a calculation model for the ejection cooling calibration of the gas turbine casing is adopted. The calculation model adopts computational fluid dynamics software to divide the gas turbine part into regions according to the surface temperature and heat exchange requirements. The boundary conditions of the solid domain are fixed temperature or fixed heat flux density. The calculation model has three interfaces with the outside world, namely, the casing inlet, the casing outlet, and the volute inlet. The casing inlet and the casing outlet are free boundaries with set vacuum degree or flow resistance value, and the volute inlet boundary conditions are gas turbine exhaust related parameters.

[0006] The beneficial effects of the present invention are:

[0007] According to the results of the injection calibration of a casing of a certain intercooled gas turbine, it can be seen that this high-precision calibration method can accurately reflect the temperature field and flow conditions inside the casing.

[0008] The high-precision calibration method for temperature and flow fields of gas turbine casing has been applied in a certain indirect-cooled gas turbine casing development project, and the calculated values ​​are in good agreement with the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the physical model of box-type flow simulation;

[0010] Figure 2 It is a schematic diagram of the gas turbine body;

[0011] Figure 3 is a schematic diagram of the exhaust volute;

[0012] Figure 4 It is a schematic diagram of the ejector;

[0013] Figure 5 It is a schematic diagram of a box body;

[0014] Figure 6 It is the high-precision calibration result of a cold-type gas turbine casing;

[0015] Among them: a is the meridian velocity cloud diagram of the box body, and b is the surface temperature cloud diagram of the gas turbine. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0017] like Figures 1 to 5As shown, a high-precision calibration device for the temperature field and flow field in a gas turbine casing based on the ejection effect of the present invention adopts a physical model for the ejection cooling calibration of the gas turbine casing. The physical model is mainly composed of four parts: a gas turbine body 1, an exhaust volute 2, an ejector 3, and a casing 4. The gas turbine body 1 is composed of a global structured grid, and the calculation accuracy is relatively high. The exhaust volute 2 and the ejector 3 cooperate with each other to form an ejection structure, which generates a negative pressure and draws the cooling air that has completed the heat exchange in the casing 4 into the exhaust pipe. The size matching of the inner and outer reducers is an important factor affecting the ejection efficiency of the casing 4. The outlet of the exhaust inner reducer and the ejector outlet are connected to the inlet of the exhaust pipe, and the ejector inlet is connected to the casing, which can more accurately simulate the flow conditions under the overall coordination of the volute, reducer and ejector.

[0018] The present invention discloses a method for high-precision calibration of temperature field and flow field in a gas turbine casing based on ejection effect. The method adopts a device for high-precision calibration of temperature field and flow field in a gas turbine casing based on ejection effect. Firstly, a calculation model for calibration of ejection cooling of a gas turbine casing is adopted. The calculation model computational fluid dynamics software divides the gas turbine part into regions according to surface temperature and heat exchange requirements. The boundary conditions of the solid domain are fixed temperature or fixed heat flux density. The casing ejection calibration calculation model has three interfaces with the outside world, namely, casing inlet, casing outlet and volute inlet. The casing inlet and casing outlet are free boundaries and vacuum degree or flow resistance value can be set. The boundary conditions of the volute inlet are gas turbine exhaust-related parameters.

[0019] According to the results of the injection calibration of a casing of a certain intercooled gas turbine, it can be seen that this high-precision calibration method can accurately reflect the temperature field and flow conditions inside the casing.

[0020] The high-precision calibration method for the temperature field and flow field of the gas turbine casing has been applied in a certain indirect-cooled gas turbine casing development project, and the calculated values ​​are in good agreement with the test results. Figure 6 shown.

Claims

1. A high-precision calibration device for temperature field and flow field in a gas turbine casing, characterized in that: A physical model for the ejection cooling verification of a gas turbine casing is adopted, which includes a gas turbine body, an exhaust volute, an ejector, and a casing. The gas turbine body is composed of a global structured grid. The exhaust volute and the ejector cooperate with each other to form an ejector structure to generate negative pressure, and to draw the cooling air that has completed the heat exchange in the casing into the exhaust pipe. The outlet of the exhaust inner reducer and the ejector outlet are connected to the inlet of the exhaust pipe, and the ejector inlet is connected to the casing, so as to accurately simulate the flow conditions under the overall cooperation of the volute, the reducer and the ejector.

2. A method for high-precision calibration of temperature field and flow field in a gas turbine casing based on ejection, using the high-precision calibration device for temperature field and flow field in a gas turbine casing according to claim 1, characterized in that: Firstly, a calculation model for the induced cooling verification of the gas turbine casing was adopted. The calculation model used computational fluid dynamics software to divide the gas turbine part into regions according to the surface temperature and heat exchange requirements. The boundary conditions of the solid domain were fixed temperature or fixed heat flux density. The calculation model had three interfaces with the outside world, namely, the casing inlet, casing outlet, and volute inlet. The casing inlet and casing outlet were free boundaries with set vacuum degree or flow resistance value, and the volute inlet boundary conditions were gas turbine exhaust related parameters.

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