RU2344302C2 - Complex air cleaning device for cleaning of gas turbine plant cycle air - Google Patents

Abstract

FIELD: motors and pumps.

SUBSTANCE: invention is related to the field of power engineering, in particular, to gas cleaning devices for cleaning of air taken from atmosphere and its preparation for supply to compressor of gas turbine plant. Complex air cleaning device for gas turbine plant cycle air comprises the following components serially installed downstream air flow suction: weather protection visor, two-section air heating device, unit of inertial cleaning, dust exhaust fans, unit of fine purification comprising air filters, bypass unit comprising bypass valves, noise killer unit connected to compressor inlet nozzle via transient air duct. Downstream weather protection visor and air flow suction, vertical shaft is installed, and weather protection visor is equipped with separating partition. Unit of inertial cleaning, air filters of fine purification, bypass unit and noise killer unit are installed beyond vertical shaft limits, parallel to its lower portion, forming horizontal section of complex air cleaning device. Lower part of vertical shaft comprises turn at 90° with radius equal to 0.30-0.35 of complex air cleaning device horizontal section height. Upstream unit of inertial cleaning, buffer section is provided with length of 0.2-0.3 of complex air cleaning device horizontal section height.

EFFECT: higher reliability of equipment operation due to reduction of inlet non-uniformity and hydraulic resistance of the whole air intake section, and also improvement of its maintenance and repair conditions.

3 cl, 2 dwg

Description

The invention relates to the field of energy, in particular to devices for the preparation of atmospheric air before feeding it to a turbocompressor of a gas turbine installation (GTU). The invention can be used in relation to axial compressors of gas turbines, as well as for air turbochargers operating in various climatic zones in metallurgy, chemistry, energy and other industries.

Particles of industrial and natural dust in atmospheric air entering the compressor flow path cause deposits in the gas-air path of the gas turbine unit and erosion of the compressor flow path. Due to erosion, profile wear and undercutting of the blades occurs, 2-4 times reducing the resource of their work, which reduces the efficiency, reliability and life of the power plant as a whole.

One of the main factors affecting the wear rate of the flow part is the concentration of particles suspended in the stream. The destructive effect of a dusty stream is directly proportional to the concentration of dust in it.

As numerous studies of Russian and foreign scientists show, in a thin surface layer of the atmosphere, the dust concentration in a power-law dependence decreases with increasing distance from the earth's surface. So, according to the VostokGIPROgaz Institute of Gas Industry, a decrease in dust concentration with height is described by the equation: K _n = a · N ^-1.6 · ^v , where K _n is the dust concentration, mg / m ³ , N is the distance to the earth’s surface, m, “a” and “c” are constants having different meanings for different types of soils. Starting from heights of 6–10 m, the decrease in dust content with height becomes (in absolute terms) insignificant. Some foreign experts are of the opinion that within the surface layer of a thickness of 10-15 m with an increase in the height of the air intake for every 3 m, dust content drops by half.

Based on these data, the vast majority of developers and suppliers of integrated air preparation devices (CLE) take the lowest point of air intake at around 6,000 or more.

Modern gas turbine engines for the most part are converted versions of well-developed highly economical aircraft engines installed in individual shelters on basements. Axial compressors of convertible engines are capable of providing economical and reliable operation of gas turbine engines provided that a uniform axial flow arrives at the inlet.

The need to organize an air intake above “6.000” when the unit axis is in the range of 1.500–2.500 marks brings to life a reduction section or a turning section, which, as a rule, is located directly in front of the entrance to the flow part.

Leading suppliers of KVOU [in Russia: VNIIGAZ, Samara Aviagaz LLC, KMPO OJSC (Kazan), NPV NEVTURBOTEST ..., in industrialized countries: ABB STAL (Sweden), AAF (USA), GE (General Electric Company USA, BB Kraftwerke Berlin GbmH (Germany), Donaldson (Denmark), EMW filtertechnik (Germany), NORDIC AIR FILTRATIONF (Denmark)] offer consumers the following typical KVOU designs:

- KVOU of container type with unilateral absorption or bilateral absorption;

- KVOU mine type;

- panel type (for gas turbine engines of high power).

A comprehensive air-cleaning device (KVOU) for gas turbines of power plants is known, consisting of blocks connected in series: an air intake with a device for heating atmospheric air, an inertial louvre separator with dust exhaust fans, a fine filter, a noise attenuation device and an adapter connecting the KVOU with a turbocompressor pipe GTU (E.I.Mikhailov, V.A. Reznik, A.A.Krinsky. "Integrated air-cleaning devices for power plants". L.: Mashinostr Oenia, 1978, p. 34-49).

The disadvantages of this device are the increased aerodynamic drag, increased noise, uneven field of air velocity, increased power consumption of auxiliary equipment.

Known air cleaning device mine type, HEU-TsN100 design LLC "Samara Aviagaz." The device consists of a weather canopy, a two-stage cyclic air purification system, a heating system, a bypass valve block, a muffler, a rotary device (for moving from the vertical part of the HEU to the horizontal one), an adapter, supporting structures and service platforms. The device comes with a lighting system, electrical equipment, instrumentation, and in the cyclone part of the HEU multicyclones of the VNIIGAZ design are used. In the second stage of cleaning, storage compact cassettes of the MPK-4 + VK-KW1 / R type manufactured by EMW (Germany) are installed. Battery cyclones are installed on the four outer sides of the rectangular air intake chamber. The camera is divided by partitions into sections, in the second part of which compact cassettes are placed.

The disadvantage of this technical solution is the increased hydraulic resistance of the dust collection unit, caused by the features of the layout of the device. In actual operating conditions when a wind load is applied according to the laws of architectural and construction aerodynamics, zones of different pressure are formed on the lateral windward and windward air intake planes (see EI Retter, Architectural and Construction Aerodynamics. - M.: Stroyizdat, 1981, §3.7. And 4.1.). The difference in pressure values from different sides of the shaft leads to an input unevenness (different speeds and mass flows through each air intake surface) and a corresponding increase in the total pressure loss in the cyclone cleaning stage. The increased hydraulic resistance of the second stage of cleaning along with the input irregularity is explained by the fact that the fine filter is located in the common channel, where the flow rate in the cleaning path is maximum.

A poorly organized rotation of 90 ° from the vertical part of the HEU to the horizontal duct is a source of additional hydraulic losses and increased, in addition to the flow unevenness at the inlet of the turbine engine, already existing behind the air purification unit. Moreover, in the design under consideration, the Boussinesq coefficient (amount of motion) characterizing the degree of flow nonuniformity can reach values of M _n = 1.3 ÷ 1.4, which for modern supersonic first compressor stages means an increase in losses in the input guide vane by 30 ÷ 60 mm of water . Art.

The increased hydraulic resistance leads to a decrease in the efficiency of the gas turbine unit and the entire gas pumping unit as a whole.

The complexity of the design cannot provide a sanitary norm for sound pressure levels that exceed 80 dB, especially when the cyclic air heating is turned on.

Closest to the claimed technical solution is the invention "Integrated air preparation device of a gas turbine installation" (GTU), protected by RF patent No. 2280706 (application No. 2004129040/06), published December 20, 2006.

The device includes sequentially installed along the suction flow: an air intake unit equipped with a weather protection visor and an anti-icing (air-heating) device, an inertial cleaning unit with dust exhaust fans; air filter unit (fine filter unit); a bypass unit with bypass valves integrated in it, a sensor for continuous monitoring of atmospheric air dust, mounted on the bypass unit housing and connected to the gas turbine control system; a sound attenuation unit connected through a transitional duct with the inlet pipe of the power plant.

The main disadvantage of the above design, as well as other known devices, is the implementation of the flow rotation - changing the direction of air movement from vertical to horizontal in the immediate vicinity of the entrance to the flow part of the gas turbine engine, which leads to a high degree of uneven flow and an increase in the total pressure loss in the gas turbine engine from the entrance to the engine to the exit from the VNA (input guide apparatus of the axial compressor) to 50 ÷ 100 mm water column The increase in losses due to input irregularity may turn out to be greater than the resistance of the entire multifunctional CVO. The places of formation of additional losses caused by the input unevenness are stiffeners supporting the front bearing of the axial compressor and a number of VNA blades. The unevenness of the input stream also causes instability and an increase in the dynamic stresses of the blade apparatus, which leads to a decrease in reliability and a decrease in engine life. A significant drawback for areas with a temperate and cold climate is the need for windy weather in the winter to carry out repair and maintenance work at high altitudes.

The technical task of the invention is to increase the reliability of the equipment by reducing the input unevenness and hydraulic resistance of the entire air intake section, consisting of KVOU, a suction duct and a section of the flowing part from its inlet section to the entrance to the first impeller, improving the conditions of routine maintenance and repair of KVOU.

The technical result is achieved due to the fact that the spatial layout and partially the design of the individual functional blocks of the well-known complex air-cleaning device containing successively installed along the suction air flow: an air intake unit equipped with a weather protection hood and an anti-icing (air-heating) device, an inertial cleaning unit with fans dust suction; air filter unit (fine filter unit); a bypass unit with bypass valves integrated in it, a sensor for continuous monitoring of atmospheric air dust, mounted on the bypass unit housing and connected to the gas turbine control system; sound attenuation unit, connected through a transitional duct with the compressor inlet, structural changes are made, namely:

- it additionally contains a vertical shaft installed along the suction of the air flow after the weather protection visor;

- the weatherproof visor is equipped with a dividing wall, offset relative to the vertical axis of the shaft away from the compressor;

- an inertial cleaning unit, fine air filters, a by-pass unit and a noise attenuation unit are located outside the vertical shaft, parallel to its lower part, forming a horizontal section of a complex air-cleaning device;

- in the lower part of the vertical shaft a 90 ° turn was made with a radius equal to 0.30-0.35 of the height of the horizontal section of the complex air-cleaning device;

- in front of the inertial cleaning unit, a buffer section is made with a length equal to 0.2-0.3 of the height of the horizontal section of the integrated air-cleaning device.

In addition, the transition duct connecting the noise suppression unit to the compressor inlet is made in the form of a confuser, the axis of which forms an angle of no more than 15 ° with the axis of the inlet, and the dividing wall on the weather protection canopy is offset by an amount equal to 0.10-0.15 the width of the upper part of the vertical shaft, which, in turn, is 0.55-0.65 of the height of the horizontal section of the air cleaning device.

The introduction of a vertical shaft after a weather protection hood containing an air intake unit with fairings and an air-heating device made it possible to place the main blocks of a complex air-cleaning device coaxially with the compressor inlet, reducing hydraulic resistance, and also facilitating the operation of the main functional blocks of the device.

Placing the dividing wall on the weather protection hood with a certain offset relative to the axis of the vertical shaft to the side of the compressor improves the uniformity of the air flow at the inlet to the inertial cleaning unit.

When the separation partition is displaced less than 0.10 of the width of the upper part of the vertical shaft, significantly lower speeds are observed in comparison with the average consumption value in the upper sections of the inertial cleaning unit. And with a displacement greater than 0.15, there are significantly lower, compared with the average consumption, speeds in the lower sections of the inertial cleaning unit.

Turning in the lower part of the vertical shaft with a radius equal to 0.30-0.35 of the height of the horizontal section of the complex air-purifying device made it possible to smoothly turn the air flow through an angle of 90 °, which reduced the hydraulic resistance and helped to stabilize the flow in the buffer section in front of the inertial block. Performing a radius greater than 0.35 of the height of the horizontal section of the integrated air-cleaning device would increase the dimensions of the horizontal section, and therefore, the entire device.

When the radius is less than 0.30, the height of the horizontal section increases the hydraulic resistance of the air flow and the length of the buffer section is insufficient to stabilize the flow after turning.

When the length of the buffer section is less than 0.2 of the height of the horizontal section of the complex air-purifying device, the air flow does not achieve the necessary alignment of the flow with the flow angles on the inertial elements, and with the length of the buffer section more than 0.3 of the height of the horizontal section, the dimensions of the device increase.

When performing a transition duct connecting the noise suppression unit to the compressor inlet pipe, with an angle between the axes of the air duct and the compressor inlet pipe more than 15 °, the level of losses at this transition sharply increases.

When the width of the upper part of the vertical shaft is less than 0.55 of the height of the horizontal section of the complex air-purifying device, the level of losses in the shaft and the irregularity of the flow behind the turn noticeably increase. And with a width of more than 0.65, the dimensions of a comprehensive air-cleaning device increase.

The design of the proposed integrated air cleaning device is illustrated in figures 1 and 2.

Figure 1 shows a General view of the CVO before entering the compressor suction chamber. It consists of a weather-protective visor 1 of a fungal shape, an air intake unit 2 (the upper part of the shaft), an air-heating device 3 (de-icing block), the lower part of the shaft 4, inertial cleaning unit 5, dust extraction system 6, dust extraction fans 7, and fine cleaning unit 8 consisting of air filters, a bypass unit 9 with bypass valves 10, a silencing unit 11, a wire duct 12, made in the form of a confuser connected to the inlet pipe of the suction chamber 14 of the gas turbine compressor, and a reference frames 13 with platforms for servicing KVOU.

Figure 2 shows the geometric dimensions of the shaft, the radius of rotation of the air flow and the remaining parts of the CVO, indicated in _W , R, N _g , in, L.

2 also shows airflow fairings 15, a dividing wall 16 mounted on a weather protection hood 1, a second section 17 of an air-heating device 3, transfer pipes 18, and a buffer section 19 formed before the airflow enters the inertia block 5 of the air-conditioning unit.

KVOU works as follows.

The air flow flowing around the tubular fairings 15 is sucked in from both sides of the weather protection hood 1 and, by means of the dividing wall 16, is turned through 180 ° and enters the air intake unit 2 of the vertical shaft.

In this part of the shaft there is a mesh grate (not shown in FIG. 1) installed to prevent large objects from getting into the in-line cyclones of the inertial unit 5. The air flow is heated by distributing pipes 18 located under the mesh grate, which the second section 17 is equipped with air-heating device 3, which protects the flow part of the HVAC from icing. In the lower part 4 of the mine, the air flow is rotated 90 ° along a radius R, the dimensions of which are determined in a given range of ratios relative to the height of the horizontal part of the CVOI - N _g . Then, through the buffer section 19, the air flow evenly enters the inlet of all direct-flow cyclones of the inertial unit 5. Dust, snow, and other aerosol particles trapped in the direct-flow cyclones enter the lower bunker of the dust collection system 6 and are thrown out of the CVO by one of the dust extraction fans 7. The pre-cleaned air then enters the air filter unit 8, then to the bypass unit 9, one or more bypass valves 10 are installed on the side walls of which are symmetrical to the KVOU axis, to the right and left. During normal operation of the KVOU, the bypass valves are closed. When the suction resistance increases above the limit due to the documentation, one or more valves open and pass part of the air into the flow part, bypassing the previous blocks of the CVO. In the downstream silencing unit 11, the main reduction in the noise level of the gas turbine engine is occurring. The air coming out of the noise attenuation unit through the duct 12, made in the form of a confuser, enters the intake duct 14.

The advantages of the proposed KVOU, compared with the known KVOU mine type, are as follows:

- the location of the main functional blocks of KVOU at a lower level relative to the ground greatly facilitates the operation of equipment and increases safety for maintenance personnel;

- the presence of a smooth docking of the vertical part of the shaft with the horizontal part of the air compressor unit has significantly reduced the hydraulic resistance of the air compressor unit and equalized air flows throughout the entire air compressor unit.

As a result of the design changes of the KVOU, the coefficient of performance (COP) of the gas turbine unit increased by 0.3-0.5%.

At present, the head sample of KVOU is mounted on the gas pipeline of the Mokrous compressor station, where it is undergoing trial operation.

Claims (3)

1. A comprehensive air-purifying device for cleaning the cyclic air of a gas turbine installation, containing a weather protection hood, a two-section air-heating device, an inertial cleaning unit, dust suction fans, a fine filter containing air filters, a bypass unit with bypass placed in it valves, a silencing unit connected through a transitional duct with the compressor inlet, characterized in that it further contains a vertical shaft installed along the suction of the air stream after the weather protection hood, and the weather protection hood is equipped with a dividing wall, while the inertial cleaning unit, fine filters, the bypass unit and the noise suppression unit are located outside the vertical shaft, parallel to its lower part, forming a horizontal section of a comprehensive air-cleaning device, at the bottom of the vertical shaft a 90 ° turn was made with a radius of 0.30-0.35 of the height of the horizontal section a complex air-purifying device, and a buffer section with a length equal to 0.2-0.3 of the height of the horizontal section of the complex air-cleaning device was made in front of the inertial cleaning unit. 2. The complex air-cleaning device according to claim 1, characterized in that the dividing wall on the weather protection hood is offset relative to the vertical axis of the shaft, away from the compressor by an amount equal to 0.10-0.15 width of the upper part of the vertical shaft, which, in its the turn is 0.55-0.65 of the height of the horizontal section of the integrated air purification device. 3. The complex air cleaning device according to claim 1, characterized in that the transitional duct is made in the form of a confuser, the axis of which forms an angle of not more than 15 ° with the axis of the compressor inlet pipe.

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