CN204254675U - A kind of distribute type cooling structure of gas-turbine combustion chamber burner inner liner - Google Patents

Abstract

The utility model relates to a distributed cooling structure of a combustion chamber flame tube of a gas turbine, which belongs to the technical field of gas turbines. The structure includes an isolation sleeve, a front splitter plate and a rear splitter plate; the isolation sleeve is arranged in the annular return air channel, and divides the annular return air channel into a cooling channel and a split air channel; the front splitter plate and the rear splitter plate Cooling holes and shunting holes are arranged on the top, and the return air enters the cooling channel and the shunting air channel through the cooling holes and the shunting holes respectively. Since the isolation sleeve divides the annular return air channel into a cooling channel and a split air channel, under the action of the cooling holes and the split holes, more air passes near the surface of the flame tube, which significantly improves the cooling of the flame tube and can be significantly improved. Reduce the wall temperature of the flame tube; at the same time, the cooling hole and the diverter hole will change the pressure loss, and the pressure loss can be adjusted according to the actual operating conditions of the combustion chamber, so as to meet the overall pressure demand.

Description

A distributed cooling structure for the combustion chamber flame cylinder of a gas turbine

technical field

The utility model relates to the technical field of gas turbines, in particular to a distributed cooling structure of a combustion chamber flame tube of a gas turbine.

Background technique

A gas turbine consists of three major components: a compressor, a combustor, and a turbine. Among them, the highest temperature zone of the gas turbine exists in the combustion chamber, which is used as a gas combustion component connecting the compressor and the turbine, converts chemical energy into heat energy, and passes hot air into the turbine to perform work. A fuel nozzle is installed at the front end of the combustion chamber. The fuel ejected from the nozzle and the incoming air are combusted in the combustion chamber. The combustion temperature can reach more than 2000 degrees Celsius and the pressure can reach 20 atmospheres. It is difficult for the outer cylinder of the combustion chamber to withstand such high pressure at high temperature. In order to reduce the temperature of the cylinder wall of the combustion chamber to ensure its strength, a flame cylinder is usually installed in the combustion chamber to reduce the heat of the outer cylinder and make it mainly under pressure.

Flame tubes are generally made of high-temperature-resistant alloys. The normal working temperature of the current flame tube metal materials is below 1000 degrees Celsius, so the flame tube must be cooled, and the rationality of the cooling structure has a great impact on the working life of the flame tube. At present, the basic cooling methods used for gas turbine flame tubes mainly include film cooling, divergent cooling, combined impingement and divergence cooling, laminate cooling, etc. The inner wall of the cylinder forms a gas film, which cools the wall of the flame cylinder on the one hand and isolates the hot gas on the other hand.

Modern advanced dry low NOx emission (DLN) combustors often require more air to enter the combustion chamber from the head of the flame tube to participate in the organization of combustion. Overall machine efficiency and reduced NOx emissions. In order to achieve this goal, the DLN combustor flame tube under high parameters often does not have large air intake holes such as main combustion holes and mixing holes, and widely adopts such as divergent cooling, impingement cooling or fin cooling, etc. Cooling technology that consumes little or no cooling air, thus providing more air for tissue combustion.

On the one hand, the long-term operation of the flame tube at high temperature is faced with creep and oxidation problems, and it suffers from thermomechanical fatigue during the continuous start-up and shutdown of the gas turbine; on the other hand, due to the uncertainty of the combustion field in the flame tube, resulting in The inhomogeneity of the heat load and the limitation of the cooling performance of the traditional cooling structure lead to uneven temperature distribution on the wall of the flame tube itself, which easily causes large thermal stress.

Utility model content

The purpose of the utility model is to provide a distributed cooling structure for the flame tube of the combustion chamber of a gas turbine, so that it can further cool the flame tube, improve cooling efficiency, and avoid high thermal stress caused by excessive temperature of the wall surface of the flame tube and uneven distribution.

In order to solve the above problems, the technical scheme of the utility model is as follows:

A distributed cooling structure for a combustion chamber flame tube of a gas turbine, wherein a diversion bushing is arranged on the outside of the flame tube, and an annular return air channel is formed between the diversion bushing and the flame tube, and the feature is that the cooling structure includes An isolation sleeve, a front splitter plate and a rear splitter plate, the isolation sleeve is arranged in the annular return air channel, and divides the annular return air channel into a cooling channel and a split air channel; the front splitter plate and the rear splitter plate are respectively It is arranged at the front end and the rear end of the spacer sleeve, and is respectively fixed on the inner wall of the guide bushing; a plurality of circumferentially arranged cooling holes and flow holes are arranged on the front splitter plate and the rear splitter plate, and the cooling The hole and the split hole communicate with the cooling channel and the split air channel respectively.

In the above technical solution, the ratio of the radial distance between the spacer sleeve and the flame cylinder to the radial space between the spacer sleeve and the flow guide bushing is between 1.5-3:1.

The technical feature of the utility model is that: the cooling hole and the distribution hole are circular or fan-shaped; the ratio of the total area of the cooling hole to the total area of the distribution hole is controlled between 2-4:1 .

The utility model has the following advantages and outstanding technical effects: ① Since the isolation sleeve divides the annular return air channel into a cooling channel and a split air channel, under the action of the cooling hole and the split hole, the return air will be divided into two parts, Make more air pass near the surface of the flame tube, significantly improve the cooling of the flame tube, and can significantly reduce the wall temperature of the flame tube; ②Cooling holes and diversion holes will change the pressure loss, and the pressure can be adjusted according to the actual operating conditions of the combustion chamber The loss is adjusted in a targeted manner to meet the overall demand for pressure.

Description of drawings

Fig. 1 is a structural schematic diagram of a gas turbine combustor flame cylinder with a cooling structure.

FIG. 2 is a cross-sectional view along line A-A of FIG. 1 .

Fig. 3 is a three-dimensional structural schematic diagram of a combustion chamber flame tube of a gas turbine with a cooling structure.

In the figure, 1- diverter bushing; 2- flame tube; 3a- front splitter plate; 3b- rear splitter plate; 4- isolation sleeve; 5- cooling channel; 6- split air channel; 7- cooling hole; 8 - Diverter holes.

Detailed ways

The principle, structure and specific implementation of the present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the utility model, but are not intended to limit the scope of the utility model.

Fig. 1 is a structural schematic diagram of a combustion chamber flame tube of a gas turbine with a cooling structure. A guide bush 1 is arranged outside the flame tube 2, and an annular return air channel is formed between the guide bush and the flame tube. The cooling structure includes a spacer The cylinder 4, the front splitter plate 3a and the rear splitter plate 3b, the isolation sleeve is arranged in the annular return air channel, and divides the annular return air channel into a cooling channel 5 and a split air channel 6, the front splitter plate 3a and The rear splitter plate 3b is respectively arranged at the front end and the rear end of the spacer sleeve 4, and is respectively fixed on the inner wall of the guide bush, and the front splitter plate 3a and the rear splitter plate 3b are provided with cooling holes 7 and splitter holes 8 communicate with the cooling channel and the split air channel respectively. The air passing through the cooling hole enters into the cooling passage, conducts convective heat exchange cooling on the outer wall of the flame tube, and makes the air enter into the split air passage through the split hole.

Fig. 2 and Fig. 3 are respectively the A-A sectional view and the three-dimensional structure schematic diagram of the utility model embodiment in Fig. 1, the radial spacing of spacer sleeve 4 apart from flame cylinder 2 and the radial space of spacer sleeve from diversion bushing 1 The ratio is between 1.5 and 3:1, so that more air passes near the surface of the flame cylinder to ensure that the cooling channel 5 has a sufficient cross-sectional area and avoid excessive pressure loss. The cooling holes 7 and the distribution holes 8 are circular or fan-shaped. The ratio of the area of the cooling hole 7 to the distribution hole 8 is controlled between 2-4:1. , to ensure that enough air enters the cooling channel 5 for cooling; the area ratio of the cooling hole 7 and the distribution hole 8 can be adjusted according to the local air pressure, so as to adapt to the local environment and meet the overall demand.

Claims (4)

1. a distributed cooling structure of a gas turbine combustor flame tube, the outside of the flame tube (2) is provided with a diversion bushing (1), and an annular return air passage is formed between the diversion bushing and the flame tube, which It is characterized in that the cooling structure includes an isolation sleeve (4), a front splitter plate (3a) and a rear splitter plate (3b), and the isolation sleeve (4) is arranged in the annular return air passage, and the annular return air The channel is divided into a cooling channel (5) and a split air channel (6); the front splitter plate (3a) and the rear splitter plate (3b) are respectively arranged at the front end and the rear end of the isolation sleeve (4), and are respectively fixed on On the inner wall of the flow guide bushing (1); on the front splitter plate and the rear splitter plate are provided with a plurality of circumferentially arranged cooling holes (7) and splitter holes (8), the cooling holes (7) and splitter holes The holes (8) communicate with the cooling channel (5) and the split air channel (6) respectively. 2. the distributive cooling structure of a kind of gas turbine combustor flame tube as claimed in claim 1, is characterized in that, spacer sleeve (4) is apart from the radial distance of flame tube (2) and spacer sleeve distance guide liner The ratio of the radial spacing of the sleeve (1) is between 1.5 and 3:1. 3. the distributed cooling structure of a kind of gas turbine combustor flame tube as claimed in claim 1 or 2, is characterized in that, the total area of described cooling hole (7) and the total area of described distribution hole (8) The ratio is controlled between 2 and 4:1. 4. The distribution cooling structure of a combustion chamber flame tube of a gas turbine as claimed in claim 3, characterized in that, the cooling holes (7) and the distribution holes (8) are circular or fan-shaped.