CN112412628A

CN112412628A - Closed type repeated cooling fluid network and closed loop terminal structure for gas turbine

Info

Publication number: CN112412628A
Application number: CN202011357878.2A
Authority: CN
Inventors: 贾兴运; 何立东; 侯启炀; 王文昊; 杨建江
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2021-02-26

Abstract

The invention discloses a closed-type repeated cooling fluid network and a closed-loop terminal structure for a gas turbine. The closed-type repeated cooling fluid network specifically refers to a hot-end part cooling that penetrates the compressor and turbine components in structure and has the functions of self-generating power and self-adaptive adjustment. The gas circuit integrated system is a cooling system fluid network composed of several typical circulating cooling closed circuits in series and parallel. Through the typical closed loop of circulating cooling and the terminal structure of the closed loop of typical circulating cooling, the pumped compressed gas can be discharged into the mainstream without passing through the air film hole after the cooling of the hot end components, and all the compressed gas is returned to the compressor, reducing the consumption of a large amount of gas. Efficiency loss and reduced performance due to compressed gas.

Description

Closed type repeated cooling fluid network and closed loop terminal structure for gas turbine

Technical Field

The invention provides a closed repeated cooling fluid network and closed loop terminal structure for a gas turbine, which is applied to an inner cooling air system (secondary air system) of a heavy-duty gas turbine core machine and belongs to the technical field of gas turbine cooling.

Background

The technical development of the traditional gas turbine has certain limitation, the premise of improving the turbine inlet temperature is the continuously improved cooling capacity and level, the novel cooling structure is designed, new materials are developed, however, objective problems cannot be avoided, a large amount of high-pressure gas needs to be extracted (consumed) from a gas compressor to cool a hot end part, most of benefit amplification brought by improving the turbine inlet temperature is consumed, and the balance and the selection are formed on the improvement of the efficiency substantially. The amount of cooling air extracted from the compressor by the currently used advanced gas turbine is more than 18% of the inlet flow of the high-pressure compressor, the British Rolls-Royce company is drawn forward, and ICAS-GT, ICAS-GT 2 and MAGIO plans are jointly developed in 1995-2009 by 9 gas turbine and aircraft engine enterprises in European Union and 5 university, and the purposes of reducing the usage amount of cooling air and reducing the fuel consumption rate are achieved. The American Society of Mechanical Engineers (ASME) and the American society of aerospace (AIAA) have conducted research and study on air system problems each year. However, many modifications and designs (such as rim seal design, disk cavity design, pre-swirl nozzle design, vortex breaker design) have not been innovative in principle and have not broken the limitations of conventional air systems, and the present invention is more intended to be a passive design and modification.

Disclosure of Invention

The invention aims to design a closed type novel cooling mode with repeatable cooling fluid and recyclable cooling fluid applied to the interior of a heavy-duty gas turbine, and provides a corresponding typical circulating cooling closed loop terminal structure based on a closed type repeated cooling fluid network design theory, so that the traditional cooling mode of a hot end part of the heavy-duty gas turbine can be broken through, the requirement on the inflow quality of the sealed cooling fluid is reduced, the pumping flow rate of a high-pressure gas compressor is reduced, and the efficiency of the whole machine is improved; in addition, the complexity of the use and control of the traditional air system regulating valve is reduced by the design of a repeated cooling system, the cooling system is enabled to be clear in level by arranging a closed cooling loop with a simple structure, the cooling process is developed in a point-to-point mode, the complexity of a gas circuit of the cooling system is reduced, the reliability of the engine cooling system is improved, and the gas circuit fault diagnosis and monitoring are facilitated; based on the self-regulation function of the cooling loop and the repeated cooling fluid network, the adaptability to different operation working conditions and loads of the engine is improved, the system self-regulates according to the external working conditions and completes a series of actions of air entraining, cooling, backflow, air exhausting and air entraining again, and the dependence on a FADEC system and manual operation is reduced.

The purpose of the invention is realized as follows:

the technical scheme adopted by the invention is an internal closed type repeated cooling fluid network and closed loop terminal structure for a gas turbine.

The cooling fluid network mainly comprises a rotor internal circulating cooling closed loop, a turbine guide vane circulating cooling closed loop and a casing circulating cooling closed loop. Their basic structural components are bleed air structures, bleed air lines, hot side cooling circulation lines, return lines and exhaust structures. The structure that the bleed structure adopted the tubular to subtract vortex pipe has added a radial pipe for preventing that the air current from leading to great pressure drop with free vortex form development, makes the air current along the radial internal flow of rotatory pipe, can effectively reduce the pressure drop. After the rotary pipe is added, when the flowing in the pipe is ensured not to reach the sonic speed, the air flow loss is mainly generated when the air flow enters and exits the pipe. The vortex reducing pipe is fixed on the positioning ring. The compressor disk cavity is divided into two cavities by the positioning ring so as to restrain the formation of strong free vortex.

For a closed-type repetitive cooling network, the main characteristics of the closed-type repetitive cooling network comprise: the structure runs through the compressor and the turbine part, the hot end part cooling gas circuit integrated system with self-generating power and self-adaptive adjusting function, and the cooling system fluid network is formed by connecting a plurality of cooling loops in series and in parallel, and the cooling fluid can be repeated and circulated. A typical cooling circuit includes: a rotor internal cooling closed loop, a turbine vane cooling closed loop, and a casing cooling closed loop. The closed type repeated cooling fluid network system can be used as a subsystem of an inner cooling air system or a secondary air system and mainly plays a role in cooling a hot end part in the air system. Each complete self-circulation cooling loop comprises a bleed air position and a bleed air structure of a certain stage of the compressor, a bleed air pipeline, a hot end part cooling pipeline, a return pipeline and an exhaust structure at a certain stage of the compressor. The typical terminal structure of the circulating cooling loop mainly comprises a gas introducing position and a gas introducing structure of the gas compressor and an exhaust structure at a certain stage of the gas compressor.

The invention has the advantages that:

the pumped compressed gas is discharged into a turbine main flow channel without passing through a gas film hole or a gap after completing a cooling task of a hot end part through a closed repeated cooling fluid network system and a circulating cooling closed loop, all the compressed gas flows back to a certain stage of the compressor through a backflow gas circuit and is discharged into the compressor main flow channel through an exhaust structure of the circulating cooling closed loop, the consumption of the compressed gas is reduced, the reduction of the overall efficiency of the compressor caused by a large amount of air pumping is reduced, and the technical bottleneck of a high-efficiency aero-engine is broken through.

The traditional secondary air system utilizes the action of air bleed (air extraction) driven by pressure difference from an air compressor to finish cooling a hot end part and discharges the hot end part into a main flow channel of a turbine in modes of an air film hole or a wheel rim gap and the like. The closed type repeated cooling fluid system cooling loop has self-power, specifically, the air compressor air entraining (air extraction) action is realized by utilizing pressure difference driving, meanwhile, the hot end part cooling of the part of compressed air is completed under the action of the pressure difference, the part of compressed air flows back to a main flow channel of the air compressor through a return pipeline, and the compressed air does not need to be externally powered in the whole approximately closed cooling loop. In addition, the cooling loop and the repeated cooling system have a self-regulation function, particularly can adapt to different operating conditions and loads of an engine, self-regulates and completes a series of actions of air entraining, cooling, backflow, air exhausting and air entraining again, and the requirement of a traditional air system on accurate control of a regulating valve and a valve is greatly reduced.

In addition, the repeated cooling fluid system can avoid the shunting and confluence phenomena (especially the rotary shunting/confluence area) of a plurality of gas paths in the secondary air system of the traditional aircraft engine, not only reduces the requirement for sealing cooling incoming flow, but also can avoid the pneumatic efficiency loss caused in the shunting and confluence process of different branch fluid, and carries out corresponding cooling loop design aiming at the required cooling position and the operating condition of a hot end part, each cooling loop is independent, the structure is simple, the fault diagnosis is easy, and the high reliability is realized.

Drawings

FIG. 1 is a closed recooling fluid network and a typical recirculating cooling closed loop internal to a heavy duty gas turbine;

FIG. 2 is a typical closed loop cooling cycle bleed air configuration for a heavy duty gas turbine;

FIG. 3 is a typical closed loop exhaust configuration for a cooling cycle for a heavy duty gas turbine;

Detailed Description

The invention solves the original problem of the air system from the design aspect, designs a brand new closed type repeated cooling fluid network based on the self-generating power and the self-regulation thought, breaks through the traditional hot end component cooling mode, reduces the flow of the gas pumped from the high-pressure compressor, and improves the efficiency of the whole machine. The design of an internal closed repeated cooling network is developed according to the design principle and method of a closed cooling circuit, a correlation mechanism of the temperature of a hot end part and air-entraining parameters is established, an air-entraining and air-exhausting terminal structure of the cooling circuit is designed, and finally a complete closed loop air path system of air-entraining, cooling, backflow, air-exhausting and air-entraining again is formed.

The invention will now be described in more detail by way of example with reference to the accompanying drawings in which:

with reference to fig. 1, the closed repetitive cooling fluid network provided by the present invention is a cooling system fluid network which runs through the whole core engine, is a hot end component cooling gas circuit integrated system with self-power generation and adaptive adjustment functions, and is formed by connecting a plurality of circulating cooling closed circuits in series and in parallel, and a typical circulating cooling closed circuit includes: a rotor internal circulation cooling closed loop 1, a turbine guide vane circulation cooling closed loop 2 and a casing circulation cooling closed loop 3.

The complete closed rotor internal circulation cooling loop 1 comprises a closed rotor internal circulation cooling loop air entraining structure 4 at an air entraining position of the air compressor, a closed rotor internal circulation cooling loop air entraining pipeline (air path) 5, a closed rotor internal circulation cooling loop cooling pipeline (air path) 6, a closed rotor internal circulation cooling loop return pipeline (air path) 7 and an closed rotor internal circulation cooling loop exhaust structure 8 at a certain stage of the air compressor. The whole circulation cooling closed loop 1 is arranged inside a compressor rotor 9 and a turbine rotor 10, and the air entraining structure 4 of the circulation cooling closed loop inside the rotor and the air exhausting structure 8 of the circulation cooling closed loop inside the rotor are arranged on one side of the compressor rotor 9. The low-temperature compressed air enters a turbine movable vane 11 through a circulating cooling closed loop cooling pipeline (air path) 6 to be cooled, then flows back to a compressor rotor 9 through a rotor internal circulating cooling closed loop backflow pipeline (air path) 7, is discharged into a compressor main flow channel through a sub-internal circulating cooling closed loop exhaust structure 8, is subjected to air bleed again through a rotor internal circulating cooling closed loop air bleed structure 4 after the main flow channel is continuously compressed, and then the actions of air bleed-cooling-backflow-exhaust-secondary air bleed are repeated to form an approximately closed circulating air path.

The complete turbine guide vane circulating cooling closed loop 2 comprises a guide vane circulating cooling closed loop air entraining structure 12 at an air entraining position of a certain stage of a gas compressor, a guide vane circulating cooling closed loop air entraining pipeline (air passage) 13, a guide vane circulating cooling closed loop hot end part cooling pipeline (air passage) 14, a guide vane circulating cooling closed loop return pipeline (air passage) 15 and a guide vane circulating cooling closed loop exhaust structure 16 at a position of a certain stage of the gas compressor. The guide vane circulating cooling closed loop air entraining structure 12 and the guide vane circulating cooling closed loop air exhaust structure 16 are both arranged on a compressor casing 17, low-temperature compressed cold air enters a turbine guide vane 18 through a guide vane circulating cooling closed loop hot end component cooling pipeline (air path) 14 to be cooled, then flows back to a compressor rotor 9 through a guide vane circulating cooling closed loop return pipeline (air path) 15, is discharged into a compressor main flow channel through the guide vane circulating cooling closed loop air exhaust structure 16, after the main flow channel is continuously compressed, air is entrained by the guide vane circulating cooling closed loop air entraining structure 12 again, and then the actions of air entraining, cooling, return flow, air exhaust and air re-entraining are repeated to form an approximately closed circulating air path.

The closed loop 3 for circulating cooling of the casing comprises a closed loop bleed air structure 19 for circulating cooling of the casing at a bleed air position of a certain stage of the compressor, a closed loop bleed air line (air path) 20 for circulating cooling of the casing, a closed loop hot end component cooling line (air path) 21 for circulating cooling of the casing, a closed loop return line (air path) 22 for circulating cooling of the casing, and a closed loop exhaust structure 23 for circulating cooling of the casing at a certain stage of the compressor.

A typical recirculating cooling closed loop compressor bleed air terminal configuration is given in connection with figure 2. The air entraining structure is an initiating end of the whole cooling loop and is a region where the interaction between a repeated cooling system and a main stream is the most complex. The bleed air structure of a typical closed circuit for recirculating cooling on the compressor side comprises a closed circuit bleed air structure 4 for recirculating cooling inside the rotor and a closed circuit bleed air structure 12 for recirculating cooling of the guide vanes.

A compressor discharge termination structure for a typical cooling self-circulation loop is shown in connection with fig. 3. The exhaust structure is the terminal of the whole cooling circuit and is also positioned at the side of the compressor, and the gas in the circulating circuit cooled by the hot end part is discharged into the main runner of the compressor from the exhaust structure, mixed with the main flow and then compressed again. The inventor designs and optimizes an exhaust structure based on local flow field analysis, determines the position of the exhaust structure, designs an airflow angle of an airflow incident main flow, and reduces the main flow pneumatic efficiency loss caused by exhaust. The exhaust structure is positioned at the front stages of the air guide structure, the specific exhaust position needs to be calculated and determined based on the cooling requirement of the hot-end component and thermodynamic parameters, and because the air guide/exhaust structure is completely arranged in the compressor, the characteristic coupling calculation of the compressor with a repeated cooling system closed cooling loop and an air guide/exhaust device is the premise of design. FIG. 3 shows an exhaust structure at the trailing edge of a compressor stator blade, with a circular exhaust hole pattern.

Claims

1. A closed-circuit repeated cooling fluid network and a closed-loop terminal structure for a gas turbine, characterized in that, comprising:

The bleed air path of the closed circuit of cooling inside the rotor;

The cooling air circuit of the hot end part of the closed loop cooling loop inside the rotor;

The compressed gas return gas path of the closed loop cooling circuit inside the rotor;

The bleed air path of the turbine guide vane cooling closed circuit;

The cooling air circuit of the hot end part of the closed loop cooling of the turbine guide vane;

The compressed gas return gas path of the turbine guide vane cooling closed circuit;

The bleed air circuit of the closed circuit for cooling the casing;

The cooling air circuit of the hot end part of the closed circuit of the casing cooling;

The compressed gas return gas path of the closed circuit for cooling the casing;

The bleed air structure of the inner cooling loop of the rotor;

The exhaust structure of the internal cooling closed circuit of the rotor;

The bleed air structure of the turbine guide vane cooling closed circuit;

The exhaust structure of the turbine guide vane cooling closed circuit;

The bleed air structure of the closed circuit of the casing cooling;

The exhaust structure of the casing cooling closed circuit.

2 . The closed-loop repeated cooling fluid network and closed-loop terminal structure for gas turbines according to claim 1 , wherein the integrated system of the cooling gas circuit for the hot-end component with the functions of self-driving power and self-adaptive adjustment is provided in the gas circuit. 3 . The system consists of several typical circulating cooling closed loops in series and parallel.

3. A closed-circuit repeated cooling fluid network and closed-circuit terminal structure for a gas turbine according to claim 1, characterized in that: the closed-circuit cooling circuit inside the rotor, the closed-circuit cooling of the turbine guide vanes and the closed-circuit cooling of the casing need to be based on the closed circuit. Based on the design theory of the repeated cooling fluid network, relying on the closed gas pipeline setting, combined with the typical closed loop terminal structure of circulating cooling, a complete closed-loop gas circuit of "bleed air-cooling-recirculation-exhaust-re-bleeding" is finally formed.

4. A kind of closed repeated cooling fluid network and closed loop terminal structure for gas turbine according to claim 1, it is characterized in that: based on the closed repeated cooling fluid network theory, the internal closed repeated cooling gas circuit of heavy-duty gas turbine is designed with high performance. gas structure.

5. The closed-circuit repeated cooling fluid network and closed-loop terminal structure for a gas turbine according to claim 1, characterized in that: based on the closed-circuit repeated cooling fluid network theory, the internal closed-type repeated cooling gas circuit of the heavy-duty gas turbine is designed with high performance exhaust. gas structure.

6. A kind of closed-type repeated cooling fluid network and closed-circuit terminal structure for gas turbine according to claim 1, characterized in that: checking the exhaust position and structure of the closed-type repeated cooling gas path inside the heavy-duty gas turbine to the compressor characteristics and surge characteristics.