Tail gas recovery system of gas turbine, gas turbine and inlet gas anti-icing method

Abstract

The invention discloses a gas turbine tail gas recovery system, a gas turbine and a gas inlet anti-icing method. The gas turbine tail gas recovery system comprises a tail gas collection device, a heat exchange device and an injection device, the tail gas collection device is arranged in an exhaust system of a gas turbine, and the opening direction of a gas inlet of the tail gas collection device is opposite to the airflow direction in the exhaust system. And the heat exchange device is arranged in an air inlet system of the gas turbine. And the injection device is arranged in an exhaust system of the gas turbine. Tail gas in the exhaust system is captured by the tail gas collecting device and then flows into the heat exchange device to exchange heat with inlet gas in the gas inlet system, and the tail gas subjected to heat exchange in the heat exchange device is exhausted into the exhaust system through the gas outlet pipeline and the injection device. Tail gas can autonomously flow in the tail gas collecting device, the heat exchange device and the injection device, inlet gas in the gas inlet system is heated, inlet gas freezing is avoided, and the energy comprehensive utilization efficiency, the working efficiency and the operation stability of the gas turbine are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of gas turbines, and particularly relates to a gas turbine tail gas recovery system, a gas turbine and an air intake anti-icing method. BACKGROUND

[0002] As a single application, the gas turbine does not have the condition of being combined with a waste heat system, tail gas will not pass through the waste heat system for waste heat recovery, and as a simple cycle gas turbine, the tail gas exhaust temperature is generally above 500 DEG C, which contains a large amount of heat energy that can be collected and utilized.

[0003] Due to the complex application scenarios of the simple cycle gas turbine, when used in cold regions, the air intake system of the gas turbine is prone to icing due to cold and humid weather, resulting in increased air intake pressure loss of the gas turbine, reducing the efficiency of the gas turbine. In severe cases, icing can block the air intake filter element or even pierce the air intake filter element and be sucked into the gas turbine, causing damage to the gas turbine blades and causing great economic losses. SUMMARY

[0004] The present application is based on the discovery and understanding of the inventors of the following facts and problems:

[0005] The inventors realized that the air intake anti-icing of the gas turbine in the related art is mostly achieved by extracting compressed hot air after the high-pressure compressor to the air intake system to locally heat the air intake, which can solve the problem of air intake system icing, but consumes the efficiency and power of the gas turbine.

[0006] The inventors also realized that the high-temperature exhaust gas of the gas turbine in the related art is not effectively utilized, and the air intake system needs to consume additional energy to ensure the safe operation of the gas turbine. Therefore, it is necessary to solve the problem of how to recover a large amount of heat energy in the exhaust gas of the gas turbine for heating the air intake system of the gas turbine, and to solve the problem of easy icing of the air intake system of the gas turbine in cold environments, so as to improve the comprehensive energy utilization efficiency and reduce the consumption of additional energy.

[0007] The present application aims to at least partially solve one of the technical problems in the related art.

[0008] To this end, the embodiments of the present application propose a gas turbine tail gas recovery system for improving the comprehensive energy utilization efficiency and reducing the consumption of additional energy.

[0009] The embodiments of the present application also propose a gas turbine.

[0010] The embodiments of the present application also propose an air intake anti-icing method.

[0011] The gas turbine tail gas recovery system of the embodiments of the present application comprises:

[0012] A tail gas collecting device is arranged in an exhaust system of a gas turbine, and an opening of an air inlet of the tail gas collecting device faces a direction opposite to a gas flow direction in the exhaust system to capture tail gas;

[0013] A heat exchange device is arranged in an air inlet system of the gas turbine, and an air inlet end of the heat exchange device is connected to the tail gas collecting device through an air inlet pipeline;

[0014] An ejector device is arranged in the exhaust system of the gas turbine, and tail gas in the exhaust system flows through the ejector device to form an induced pressure area in the ejector device, and an air outlet end of the air outlet pipeline extends into the induced pressure area in the ejector device, and the induced pressure area has a pressure lower than that in the air outlet pipeline to induce the tail gas in the air outlet pipeline;

[0015] After the tail gas in the exhaust system is captured by the tail gas collecting device, the tail gas flows into the heat exchange device to exchange heat with inlet gas in the air inlet system, and the tail gas after heat exchange in the heat exchange device is discharged into the exhaust system through the air outlet pipeline and the ejector device.

[0016] The tail gas recovery system of the gas turbine according to the embodiments of the present application can utilize kinetic energy of the tail gas to form flow in the tail gas collecting device, the heat exchange device and the ejector device, and does not need other additional power equipment to drive gas flow, and can utilize heat energy of the tail gas to heat inlet gas in the air inlet system of the gas turbine to increase the temperature of the inlet gas, avoid icing, improve comprehensive utilization efficiency of energy, and improve working efficiency and operation stability of the gas turbine.

[0017] In some embodiments, the tail gas collecting device includes a gas collecting cover, the gas collecting cover has an air inlet end and an air outlet end in the gas flow direction in the exhaust system, and a cross-sectional dimension of an inner cavity of the gas collecting cover gradually decreases along the gas flow direction in the exhaust system.

[0018] In some embodiments, the gas collecting cover is funnel-shaped, and a larger opening end of the gas collecting cover faces the gas flow direction of the exhaust system.

[0019] In some embodiments, a control valve and a flow meter are further included, the control valve and the flow meter are arranged on the air inlet pipeline, and the control valve adjusts an opening degree thereof according to a flow parameter obtained by the flow meter to adjust the flow in the air inlet pipeline.

[0020] In some embodiments, the heat exchange device includes an outer shell, and the outer shell has a flow channel therein, and a total cross-sectional dimension of the flow channel is greater than a cross-sectional dimension of an inner cavity of the air inlet pipeline.

[0021] In some embodiments, the number of flow channels is multiple, and the multiple flow channels are arranged side by side and are all in communication with the air inlet pipe and the air outlet pipe.

[0022] And / or, the shell comprises a pipe body and heat dissipation fins arranged on the outer wall of the pipe body, and the pipe body defines the flow channels;

[0023] And / or, the heat exchange device is arranged at the front side of the air inlet filter element in the air inlet system, and the number of heat exchange devices is multiple groups.

[0024] In some embodiments, the ejector device comprises an ejector pipe, the inner cavity of the ejector pipe has a contraction section, a cylinder section and a diffusion section, the cylinder section is located between the contraction section and the diffusion section, the axis direction of the ejector pipe is parallel to the airflow direction of the exhaust system, and the contraction section, the cylinder section and the diffusion section are arranged in sequence along the airflow direction of the exhaust system.

[0025] The air outlet end of the air outlet pipe extends into the cylinder section, and the exhaust gas in the exhaust system flows through the contraction section, the cylinder section and the diffusion section in sequence to form the pressure injection area at the cylinder section.

[0026] In some embodiments, one end of the air outlet pipe adjacent to the ejector pipe has an exhaust section, and the airflow direction of the exhaust section is parallel to the airflow direction in the ejector pipe.

[0027] And / or, the inner cavity of the cylinder section is of equal cross section, the cross-sectional size of the inner cavity of the contraction section gradually decreases along the airflow direction, and the cross-sectional size of the inner cavity of the diffusion section gradually increases along the airflow direction.

[0028] And / or, the ejector pipe is located downstream of the exhaust gas collection device, and the ejector pipe and the exhaust gas collection device are arranged staggered along the airflow direction in the exhaust system.

[0029] The gas turbine of the embodiment of the present application comprises the gas turbine exhaust gas recovery system of any one of the above-mentioned embodiments.

[0030] The air inlet ice prevention method of the embodiment of the present application comprises:

[0031] The gas turbine exhaust gas recovery system of any one of the above-mentioned embodiments is arranged between the air inlet system and the exhaust system of the gas turbine.

[0032] It is judged whether the initial air inlet temperature of the gas turbine is less than a first threshold value;

[0033] If yes, a control valve on the air inlet pipe in the gas turbine exhaust gas recovery system is opened;

[0034] a current intake temperature in the intake system, and determining whether the current intake temperature is between a second threshold value and a third threshold value, wherein the third threshold value is greater than the second threshold value, and the second threshold value is greater than the first threshold value;

[0035] If not, increasing the opening of the control valve when the current intake temperature is less than the second threshold value, and decreasing the opening of the control valve when the current intake temperature is greater than the third threshold value. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a schematic diagram of a gas turbine exhaust gas recovery system according to an embodiment of the present application.

[0037] Figure 2 is a schematic diagram of a connection between a gas turbine exhaust gas recovery system and a gas turbine according to an embodiment of the present application.

[0038] Figure 3 is a schematic diagram of a connection between a gas turbine exhaust gas recovery system and a gas turbine according to an embodiment of the present application.

[0039] Figure 4 is a schematic diagram of an exhaust gas collecting device in a gas turbine exhaust gas recovery system according to an embodiment of the present application.

[0040] Figure 5 is a schematic diagram of a heat exchanging device in a gas turbine exhaust gas recovery system according to an embodiment of the present application.

[0041] Figure 6 is a schematic diagram of an ejector device in a gas turbine exhaust gas recovery system according to an embodiment of the present application.

[0042] REFERENCE NUMERALS:

[0043] 100, gas turbine exhaust gas recovery system; 200, gas turbine;

[0044] 1, exhaust gas collecting device; 11, gas collecting cover;

[0045] 2, heat exchanging device; 21, pipe body; 22, heat dissipation fin;

[0046] 3, ejector device; 31, ejector pipe; 311, converging section; 312, cylindrical section; 313, diverging section;

[0047] 4, intake pipe; 41, control valve; 42, flow meter;

[0048] 5, exhaust pipe;

[0049] 61, intake system; 62, exhaust system. DETAILED DESCRIPTION

[0050] Embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments described below are exemplary and are intended to be illustrative of the present application and are not to be construed as limiting the present application.

[0051] A gas turbine exhaust gas recovery system 100 according to an embodiment of the present application is described below.

[0052] Referring to Figures 1 to 6 The gas turbine exhaust gas recovery system 100 according to an embodiment of the present application includes an exhaust gas collecting device 1, a heat exchanging device 2 and an ejector device 3.

[0053] The exhaust gas collecting device 1 is arranged in an exhaust system of the gas turbine 200, and the opening of the gas inlet of the exhaust gas collecting device 1 faces in the opposite direction to the flow direction of the exhaust system to capture the exhaust gas flowing at high speed and having kinetic energy.

[0054] The heat exchanging device 2 is arranged in an air intake system 61 of the gas turbine 200, and the gas inlet of the heat exchanging device 2 is connected to the exhaust gas collecting device 1 through an air inlet pipeline 4. The ejector device 3 is arranged in the exhaust system of the gas turbine 200, and the exhaust gas flowing in the exhaust system and having kinetic energy flows through the ejector device 3 to form a pressure zone in the ejector device 3. The gas outlet of the heat exchanging device 2 is connected to an air outlet pipeline 5, and the gas outlet of the air outlet pipeline 5 extends into the pressure zone of the ejector device 3. The pressure in the pressure zone is lower than the pressure in the air outlet pipeline 5 to eject the exhaust gas in the air outlet pipeline 5.

[0055] The heat exchanging device 2 can be a finned heat exchanger, a loop heat exchanger or the like. The heat exchanging device 2 can be designed in a modular manner, which facilitates assembly and installation according to the space of the air intake system 61, and also facilitates maintenance and replacement.

[0056] The exhaust gas flowing at high speed and having kinetic energy in the exhaust system is captured by the exhaust gas collecting device 1 and then flows into the heat exchanging device 2 to exchange heat with the intake gas in the air intake system 61. The exhaust gas after heat exchange in the heat exchanging device 2 is discharged into the exhaust system through the air outlet pipeline 5 and the ejector device 3.

[0057] After the exhaust gas flowing at high speed and having kinetic energy in the exhaust system enters the gas inlet of the exhaust gas collecting device 1, the exhaust gas will continue to flow along the subsequent air inlet pipeline 4 into the heat exchanging device 2 and then flow to the ejector device 3 through the air outlet pipeline. Of course, the ejector device 3 also provides an ejecting pressure for the exhaust gas in the air outlet pipeline to promote the exhaust gas in the air outlet pipeline to be discharged. The gas turbine exhaust gas recovery system 100 according to the present embodiment can utilize the kinetic energy possessed by the exhaust gas itself to form a flow in the exhaust gas collecting device 1, the heat exchanging device 2 and the ejector device 3, and does not need other additional power equipment to drive the flow of the gas.

[0058] The high-temperature tail gas can heat the intake gas in the intake system 61 of the gas turbine 200 by using the heat energy of the tail gas when the tail gas flows through the heat exchange device 2, so that the intake gas is heated to increase the temperature of the intake gas, avoid icing of the intake gas, avoid blocking or breaking of the intake filter element, and thus improve the energy comprehensive utilization efficiency of the gas turbine 200 and improve the working efficiency and the operation stability of the gas turbine 200.

[0059] The gas turbine tail gas recovery system 100 of the embodiment of the application is described below.

[0060] Referring to Figures 1 to 6 The gas turbine tail gas recovery system 100 includes a tail gas collecting device 1, a heat exchange device 2, and an ejector device 3.

[0061] The tail gas collecting device 1 is arranged in the exhaust system of the gas turbine 200, and the opening of the intake port of the tail gas collecting device 1 faces the direction opposite to the airflow direction in the exhaust system to collect the tail gas flowing at high speed and having kinetic energy.

[0062] As shown in Figure 4 The tail gas collecting device 1 includes a gas collecting hood 11, and the gas collecting hood 11 is funnel-shaped. The opening of the gas collecting hood 11 faces the airflow direction of the exhaust system. In other words, the gas collecting hood 11 has an intake end and an exhaust end in the airflow direction of the exhaust system. The cross-sectional size (cross-sectional area) of the inner cavity of the gas collecting hood 11 gradually decreases along the airflow direction of the exhaust system. The high-speed flowing tail gas in the exhaust system flows into the inner cavity of the gas collecting hood 11, and the high-speed flowing tail gas has kinetic energy flowing to the subsequent heat exchange device 2 and the ejector device 3. Without increasing the active flow of the tail gas by the power equipment, the self-operation of the system can be realized.

[0063] The heat exchange device 2 is arranged in the intake system 61 of the gas turbine 200, and the intake end of the heat exchange device 2 is connected to the tail gas collecting device 1 through the intake pipeline 4.

[0064] As shown in Figure 5As shown in the figure, the heat exchange device 2 of the embodiment of the present application comprises a pipe body 21 and heat dissipation fins 22 arranged on the outer wall of the pipe body 21, and a flow channel is defined in the pipe body 21. The number of the pipe body 21 can be multiple, thereby forming multiple flow channels arranged in parallel, so that the heat exchange device 2 has a larger heat exchange area in the air intake system 61. The multiple flow channels are arranged side by side and are all connected with the air inlet pipe 4 and the air outlet pipe 5, and the total cross-sectional size of the flow channels is larger than the cross-sectional size of the inner cavity of the air inlet pipe 4. When the exhaust gas enters the flow channel, the flow rate and pressure can be reduced, and the high-temperature exhaust gas in the pipe body 21 and the intake gas in the air intake system 61 are indirectly contacted and exchanged heat through the outer wall of the pipe body 21 and the heat dissipation fins 22, thereby improving the heat exchange effect. The arrangement of multiple pipe bodies 21 can improve the uniformity of the gas temperature in different regions of the air intake system 61, and the pipe bodies 21 are evenly arranged in the air intake system 61, so that the insufficient heat exchange in the local region does not cause the water in the humid gas to freeze.

[0065] The heat exchange device 2 of the embodiment of the present application is arranged at the front side of the air intake filter element in the air intake system 61, so that the water in the gas does not condense after entering the air intake filter element, and the air intake filter element is prevented from freezing and being blocked. The number of the heat exchange device 2 can be multiple, and the heat exchange device 2 is arranged reasonably according to the volume, gas flow rate and spatial position of the air intake system 61, thereby improving the heat exchange effect.

[0066] The air inlet pipe 4 is provided with a control valve 41 and a flow meter 42, the flow meter 42 is used to obtain the flow rate of the exhaust gas in the air inlet pipe 4, and the control valve 41 adjusts the opening degree thereof according to the flow rate parameter obtained by the flow meter 42 to adjust the flow rate in the air inlet pipe 4. The control valve 41 can be an electric valve, a hydraulic valve or a pneumatic valve. Since the temperature of the gas entering the air intake system 61 is different under different working conditions, for example, in a high-altitude area with large diurnal temperature difference, the intake gas does not need to be heated in the daytime, but needs to be heated at night, so the flow rate of the exhaust gas flowing to the heat exchange device 2 needs to be determined according to different time periods and different gas temperatures. For another example, when the gas turbine 200 works under high load, the intake amount is large, and when the gas turbine 200 works under low load, the intake amount is small, so the flow rate of the exhaust gas flowing to the heat exchange device 2 also needs to be adjusted, so that the intake temperature is within a certain threshold range.

[0067] Further, one end of the air inlet pipe 4 close to the gas collecting cover 11 is a gas collecting pipe section, and the included angle between the axis of the gas collecting pipe section and the axis of the gas collecting cover 11 is greater than 120 degrees, so that the collected high-speed flowing exhaust gas can enter the air inlet pipe 4. When the air inlet pipe 4 is arranged, the flow directions of the exhaust gas in different sections of the air inlet pipe 4 need to be avoided as much as possible, so as to improve the smoothness of the exhaust gas flow. When the air inlet pipe 4 needs to be turned, an arc-shaped elbow pipe with a large radius can be used for connection, so as to reduce the loss of kinetic energy of the exhaust gas in the air inlet pipe 4.

[0068] The ejector device 3 is arranged in the exhaust system of the gas turbine 200. The exhaust gas with kinetic energy in the exhaust system flows through the ejector device 3 to form an ejection pressure zone in the ejector device 3. The outlet end of the heat exchange device 2 is connected to the outlet pipe 5. The outlet end of the outlet pipe 5 extends to the ejection pressure zone in the ejector device 3. The air pressure in the ejection pressure zone is lower than the air pressure in the outlet pipe 5 to eject the exhaust gas in the outlet pipe 5.

[0069] like Figure 6 As shown, specifically, the ejector device 3 includes an ejector tube 31. The inner cavity of the ejector tube 31 comprises a contracting section 311, a cylindrical section 312, and a diffuser section 313. The cylindrical section 312 is located between the contracting section 311 and the diffuser section 313. The axis of the ejector tube 31 is parallel to the airflow direction of the exhaust system. The contracting section 311, the cylindrical section 312, and the diffuser section 313 are arranged in sequence along the airflow direction of the exhaust system. The inner cavity of the cylindrical section 312 has a uniform cross-section. The cross-sectional dimensions of the inner cavity of the contracting section 311 gradually decrease along the airflow direction, while the cross-sectional dimensions of the inner cavity of the diffuser section 313 gradually increase along the airflow direction.

[0070] The outlet end of the outlet pipe extends into the column section 312. Exhaust gas with kinetic energy in the exhaust system flows sequentially through the contraction section 311, the column section 312, and the diffusion section 313, forming a pressure-inducing zone at the column section 312. This allows the exhaust gas in the outlet pipe to be ejected, improving exhaust efficiency and promoting smoother exhaust gas flow in the system.

[0071] The ejector pipe 31 is located downstream of the exhaust gas collecting device 1. The ejector pipe 31 and the exhaust gas collecting device 1 are staggered along the airflow direction in the exhaust system to prevent the exhaust gas discharged from the outlet pipe from being collected again by the exhaust gas collecting device 1. At the same time, it also prevents the exhaust gas collecting device 1 from interfering with the exhaust entering the ejector pipe 31, causing the air flow rate, flow velocity and direction entering the ejector pipe 31 to be blocked and interfered with by the gas collecting hood 11, thereby avoiding affecting the formation of the pressure zone in the ejector pipe 31.

[0072] In this embodiment, the outlet duct has an exhaust section at one end adjacent to the ejector tube 31. The airflow in this exhaust section is parallel to the airflow within the ejector tube 31, improving the smooth flow of exhaust gas from the outlet duct into the exhaust system. Of course, the airflow in the exhaust section can also form a predetermined angle with the airflow within the ejector tube 31, typically greater than 90 degrees, to facilitate the flow of exhaust gas within the outlet duct along the airflow within the ejector tube 31.

[0073] The exhaust gas with kinetic energy in the exhaust system is collected by the exhaust gas collecting device 1, and then flows into the heat exchange device 2 to exchange heat with the intake gas in the intake system 61. The exhaust gas after heat exchange in the heat exchange device 2 is discharged into the exhaust system through the exhaust pipe 5 and the injection device 3. In other words, the high-speed exhaust gas with kinetic energy in the exhaust system will continue to flow into the heat exchange device 2 through the subsequent intake pipe 4 and the exhaust pipe to the injection device 3 after entering the intake port of the exhaust gas collecting device 1. Of course, the injection device 3 will also provide injection pressure for the exhaust gas in the exhaust pipe to discharge the exhaust gas. The gas turbine exhaust gas recovery system 100 of the embodiment can utilize the kinetic energy of the exhaust gas itself to form flow in the exhaust gas collecting device 1, the heat exchange device 2 and the injection device 3, without other additional power equipment to drive the gas flow.

[0074] When the high-temperature exhaust gas flows through the heat exchange device 2, the heat energy of the exhaust gas itself can be utilized to exchange heat with the intake gas in the intake system 61 of the gas turbine 200, so that the intake gas is heated to increase the temperature, avoid ice formation, avoid the filter core of the intake system 61 from being blocked or broken, thereby improving the energy comprehensive utilization efficiency of the gas turbine 200 and the working efficiency and the stability of the gas turbine 200.

[0075] Compared with the related art of extracting high-pressure compressor compressed hot air to locally heat the intake gas of the intake system 61, and heating the intake gas in the intake system 61 by consuming additional electric energy and fuel, the embodiment of the present application can recover the waste heat of the exhaust gas, and utilize the kinetic energy of the exhaust gas itself to realize the autonomous circulation operation of the gas turbine exhaust gas recovery system 100, thereby greatly improving the stability and practicability of the equipment operation. The embodiment of the present application utilizes the characteristics of the exhaust gas of the gas turbine 200 carrying a large amount of heat energy and the requirement of the intake system 61 to ensure that no ice is formed, thereby achieving the purpose and requirement of preventing ice formation in the intake system 61 without additional energy consumption under the premise of ensuring the thermal efficiency and power of the gas turbine 200. The heat loss in the intake of the gas turbine 200 and the exhaust gas is complementary, and finally the energy is utilized efficiently.

[0076] As shown in Figure 2 and Figure 3 , the gas turbine 200 of the embodiment of the present application comprises the gas turbine exhaust gas recovery system 100 of any one of the above embodiments. At least part of the beneficial effects achieved by the gas turbine 200 of the embodiment of the present application are the same as the beneficial effects achieved by the gas turbine exhaust gas recovery system 100 in the above embodiments, and therefore will not be described again.

[0077] The intake ice prevention method of the embodiment of the present application comprises:

[0078] S101, arranging the gas turbine exhaust gas recovery system in any of the above embodiments between the gas turbine intake system and the exhaust system.

[0079] S102, determining whether the initial intake temperature of the gas turbine is less than a first threshold value. The first threshold value can be 0 degrees Celsius to 5 degrees Celsius, for example, when the first threshold value is 0 degrees Celsius, if the initial intake temperature is lower than 0 degrees Celsius, icing phenomenon is likely to occur in the intake system, so the intake needs to be heated. For example, the first threshold value can be set to 3 degrees Celsius, when the initial intake temperature is lower than 3 degrees Celsius, the intake system has the risk of icing, so the intake can be heated in advance. To ensure the normal and stable operation of the system.

[0080] Of course, the first threshold value can also be adjusted according to the influence of the intake temperature on the working efficiency of the gas turbine, for example, when the intake temperature reaches 10 degrees Celsius, it helps to improve the working efficiency of the gas turbine, then the first threshold value can be set to 10 degrees Celsius, not only to prevent icing, but also to ensure the working efficiency of the gas turbine stable.

[0081] S103, if yes, open the control valve on the intake pipeline in the gas turbine exhaust gas recovery system. When the initial intake temperature of the gas turbine is less than the first threshold value, it means that there is a risk of icing or an impact on the working efficiency of the gas turbine, so the control valve can be opened to utilize the heat and kinetic energy of the exhaust gas to realize the autonomous flow of the exhaust gas in the gas turbine exhaust gas recovery system and heat the intake gas.

[0082] S104, obtain the current intake temperature in the intake system, and determine whether the current intake temperature is between a second threshold value and a third threshold value, wherein the third threshold value is greater than the second threshold value, and the second threshold value is greater than the first threshold value.

[0083] Because the working condition of the gas turbine will change, the intake of the gas turbine will also change, and the ambient temperature will also change with the alternation of day and night, therefore, the gas flow in the gas turbine exhaust gas recovery system needs to be adjusted periodically to ensure that the temperature of the intake gas is always within a stable threshold range.

[0084] The current intake temperature can be obtained periodically at intervals T, for example, the intake temperature is obtained every 5 to 30 minutes, and a determination and adjustment is made. Alternatively, the intake temperature can be obtained in real time, and the control valve is adjusted at the first time when the intake temperature is greater than the third threshold value or less than the second threshold value.

[0085] S105, if no, when the current intake temperature is less than the second threshold value, increase the opening of the control valve, and when the current intake temperature is greater than the third threshold value, decrease the opening of the control valve.

[0086] The intake temperature of the gas turbine is not too low to avoid icing, and of course, the intake temperature is not too high, therefore, the temperature of the intake gas of the intake system of the gas turbine is reasonably controlled between the second threshold value and the third threshold value, which can guarantee the high efficient and stable operation of the gas turbine.

[0087] In the present application, unless specifically defined and limited otherwise, the terms "mount", "connect", "connection", "fixed", and like terms should be construed as broadly as possible, for example, can be fixed connection, can be detachable connection, or integrated; can be mechanical connection, or electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0088] In the present application, unless specifically defined and limited otherwise, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the first feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the first feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0089] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction.

[0090] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A gas turbine exhaust gas recovery system characterized by, The application relates to a tail gas collecting device, a heat exchanging device and an ejector device. The tail gas collecting device is arranged in an exhaust system of a gas turbine, and the opening of the inlet of the tail gas collecting device faces the direction opposite to the gas flow direction in the exhaust system to collect tail gas. The heat exchanging device is arranged in an air inlet system of the gas turbine, and the inlet end of the heat exchanging device is connected with the tail gas collecting device through an air inlet pipeline. The ejector device is arranged in the exhaust system of the gas turbine, and the tail gas in the exhaust system flows through the ejector device to form a pressure zone in the ejector device. The tail gas collected by the tail gas collecting device flows into the heat exchanging device to exchange heat with the air in the air inlet system.

2. The gas turbine exhaust gas recovery system of claim 1, wherein, The tail gas in the heat exchanging device is discharged into the exhaust system through the air outlet pipeline and the ejector device.

3. The gas turbine exhaust gas recovery system of claim 2, wherein, The tail gas collecting device comprises a collecting cover, and the collecting cover has an inlet end and an outlet end in the gas flow direction of the exhaust system.

4. The gas turbine exhaust gas recovery system of claim 3, wherein, The cross-sectional size of the inner cavity of the collecting cover gradually decreases along the gas flow direction of the exhaust system.

5. The gas turbine exhaust gas recovery system of claim 1, wherein, The collecting cover is funnel-shaped, and the end with the larger opening of the collecting cover faces the gas flow direction of the exhaust system.

6. The gas turbine exhaust gas recovery system of claim 5, wherein, A control valve and a flow meter are arranged on the air inlet pipeline. The heat exchanging device comprises a shell, and the shell has a flow channel. The shell comprises a pipe body and heat dissipation fins arranged on the outer wall of the pipe body.

7. The gas turbine exhaust gas recovery system of claim 1, wherein, The heat exchanging device is arranged on the front side of an air filter element in the air inlet system, and the heat exchanging device comprises multiple groups. The ejector device comprises an ejector pipe, and the inner cavity of the ejector pipe has a contraction section, a cylinder section and a diffusion section.

8. The gas turbine exhaust gas recovery system of claim 7, wherein, The outlet end of the air outlet pipeline extends into the cylinder section. The end of the air outlet pipeline adjacent to the ejector pipe has an exhaust section, and the gas flow direction of the exhaust section is parallel to the gas flow direction in the ejector pipe. The inner cavity of the cylinder section is of equal cross section, the cross-sectional size of the inner cavity of the contraction section gradually decreases along the gas flow direction, and the cross-sectional size of the inner cavity of the diffusion section gradually increases along the gas flow direction. And / or, the ejector is located downstream of the tail gas collection device, the ejector and the tail gas collection device being misaligned along the direction of gas flow in the exhaust system.

9. A gas turbine engine characterized by, A gas turbine tail gas recovery system as claimed in any one of claims 1 to 8.

10. An air intake anti-icing method, characterized by, Comprising: A gas turbine tail gas recovery system as claimed in any one of claims 1 to 8 is arranged between an intake system and an exhaust system of a gas turbine; Determining whether an initial intake temperature of the gas turbine is less than a first threshold value; If yes, opening a control valve on the intake duct in the gas turbine tail gas recovery system; Obtaining a current intake temperature in the intake system and determining whether the current intake temperature is between a second threshold value and a third threshold value, wherein the third threshold value is greater than the second threshold value, and the second threshold value is greater than the first threshold value; If no, increasing the opening of the control valve when the current intake temperature is less than the second threshold value, and decreasing the opening of the control valve when the current intake temperature is greater than the third threshold value.

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