A recirculating steam turbine structure

Abstract

The utility model relates to a reflux steam turbine structure, and relates to the technical field of steam turbine energy recovery, which includes a steam turbine, a steam collecting structure for collecting low-temperature and low-pressure steam discharged from the steam turbine, a pressurizing structure for heating and pressurizing the low-temperature and low-pressure steam, and a reflux pipeline for returning the heated and pressurized steam to the steam turbine for reuse. The utility model can collect the low-temperature and low-pressure steam discharged from the steam outlet of the steam turbine, heat and pressurize the collected low-temperature and low-pressure steam through the pressurizing structure, and then send the heated and pressurized steam back to the steam inlet of the steam turbine for reuse through the reflux pipeline, thereby omitting the process of condensing the exhausted steam and returning it to the boiler for reheating, and effectively improving the energy recovery rate.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbine energy recovery, in particular to a reflow type steam turbine structure. Background Art

[0002] A steam turbine is a device that converts high-temperature steam into power. The high-temperature and high-pressure steam from the boiler first passes through a fixed nozzle. During this process, the steam accelerates and expands, and its thermal energy is converted into the kinetic energy of high-speed airflow. These high-speed airflows are sprayed onto the blades, driving the rotor equipped with blades to rotate, thereby converting the kinetic energy of the steam into mechanical energy. In a steam turbine, after the steam drives the impeller to rotate and do work, its pressure and temperature will drop. This part of the unused steam can be sent back to the boiler for reheating, thereby maximizing energy utilization.

[0003] At present, a Chinese patent application with publication number CN216841852U and publication date June 28, 2022 proposes a steam turbine heat recovery system, including a steam turbine unit, a unit inlet pipe arranged at the air inlet end of the steam turbine unit, a boiler arranged at the other end of the unit inlet pipe, a unit outlet pipe arranged at the exhaust end of the steam turbine unit, a tee pipe arranged at the other end of the unit outlet pipe, and an insulated inlet pipe arranged at the top of the tee pipe.

[0004] The used steam can be transported to the insulation component and preheating component through the three-way pipe. The insulation component can insulate the unit inlet pipe during the high-temperature and high-pressure steam transportation process, thereby avoiding excessive heat loss of the transported steam.

[0005] In this technical solution, the used high-temperature steam needs to be condensed into water through a condenser and then sent into a boiler to be heated into high-temperature steam. A large amount of energy has been lost in the stage where the high-temperature steam is condensed into water, resulting in a waste of energy. Utility Model Content

[0006] In order to reduce the energy waste in the process of high-temperature steam being condensed into water and then sent into a boiler for heating, the utility model provides a reflux steam turbine structure.

[0007] The utility model provides a recirculating steam turbine structure, which adopts the following technical solutions:

[0008] A return flow steam turbine structure comprises a steam turbine, a steam collecting structure, a pressurizing structure and a return flow pipeline, wherein the steam turbine is provided with a steam inlet end and a steam outlet end, and the steam inlet end of the steam turbine is connected to a boiler; the steam collecting structure comprises a steam collecting end and a steam transmission end, the steam collecting end is connected to the steam outlet end, the steam transmission end is connected to the pressurizing structure, and the pressurizing structure is connected to the steam inlet end of the steam turbine via a return flow pipeline.

[0009] Through this technical solution, the low-temperature and low-pressure steam discharged from the steam outlet of the steam turbine is collected by using a steam collecting structure, and the collected low-temperature and low-pressure steam is heated and pressurized by a pressurizing structure. When it reaches the use standard, the heated and pressurized steam is sent back to the steam inlet of the steam turbine through a reflux pipeline. This process omits the process of condensing and collecting the exhaust steam discharged from the steam turbine and sending it back to the boiler for reheating, which reduces the heat loss during condensation and effectively improves the energy recovery rate.

[0010] Optionally, a secondary steam inlet is arranged between each stage of the impeller of the steam turbine, and a first three-way pipe is also arranged between the pressurizing structure and the steam inlet end of the steam turbine, one of the outlets of the first three-way pipe is connected to the secondary steam inlet, the inlet of the first three-way pipe is connected to the pressurizing structure, and the other outlet of the first three-way pipe is connected to the steam inlet end of the steam turbine.

[0011] By adopting this technical solution, the steam heated and pressurized by the pressurized structure is divided into two paths, one of which is sent back to the steam inlet of the steam turbine to be mixed with the steam generated by the boiler for use, and the other is sent to the secondary steam inlet between the impellers of each stage of the steam turbine to replenish the energy lost between the impellers of each stage and improve the operating efficiency of the subsequent impellers of each stage. By adopting this technical solution, the heated and pressurized steam can be flexibly distributed according to the use of the steam turbine, saving energy consumption.

[0012] Optionally, a first flow valve is further provided between the first three-way pipe and the secondary steam inlet.

[0013] By adopting this technical solution, the first flow regulating valve installed before the secondary steam inlet can accurately control the flow of the steam after temperature and pressure increase entering the secondary steam inlet. By accurately controlling the flow entering the secondary steam inlet, the stable and efficient operation of the impellers at all levels can be guaranteed, and the maintenance cost can be reduced.

[0014] Optionally, a secondary pressurization structure is installed between the first three-way pipe and the steam inlet end of the turbine, and a first one-way valve is installed between the secondary pressurization structure and the first three-way pipe. The installation direction of the first one-way valve is that the first three-way pipe flows toward the secondary pressurization structure.

[0015] By adopting this technical solution, due to the different steam temperatures and pressures used between the turbine impellers at each stage and between the steam inlet end of the turbine, the steam heated and pressurized by the pressurization structure cannot be supplied to the secondary steam inlet and the steam inlet end of the turbine at the same time. A secondary pressurization structure is installed on the first three-way pipe and the steam inlet end of the turbine, and the steam heated and pressurized by the pressurization structure can be heated and pressurized for a second time, and the steam heated and pressurized by the pressurization structure can be sent to the secondary steam inlet, and the steam that has passed through the secondary pressurization structure can be sent to the steam inlet end of the turbine. The first one-way valve can prevent the steam from flowing backwards in the pipeline, ensuring that the steam can flow stably in the pipeline. In this way, the steam that has been heated and pressurized can be used at the same time, and the utilization rate of the temperature and pressure treatment of the exhaust steam can be improved.

[0016] Optionally, a second flow valve is further provided between the secondary pressurization structure and the steam inlet end of the steam turbine.

[0017] Through this technical solution, the second flow valve set can accurately control the steam flow entering the steam inlet end of the turbine after heating and pressure increase. At the same time, in conjunction with the adjustment of the first flow valve at the secondary steam inlet, the steam after heating and pressure increase can be flexibly distributed, and the steam flow allowed to pass by the second flow valve can be flexibly controlled according to the operating status of the turbine, so that the total flow of steam entering the turbine from the boiler and the secondary pressurized steam entering the turbine remains stable, ensuring that the turbine can operate stably and reducing energy consumption and operating costs.

[0018] Optionally, the steam transmission ends of the pressurizing structure and the steam collecting structure are further provided with a second one-way valve, and the installation direction of the second one-way valve is such that the steam flows from the steam collecting structure to the pressurizing structure.

[0019] Through this technical solution, the second one-way valve can prevent the steam that has been heated and pressurized by the pressurized structure from being diverted in the pipeline, affecting the normal circulation of steam in the pipeline, and ensuring that the steam can flow stably from the output end of the steam collecting structure to the pressurized structure.

[0020] Optionally, a second three-way pipe is further arranged between the steam transmission end of the steam collecting structure and the second one-way valve, the inlet of the second three-way pipe is connected to the steam transmission end, the outlet of the second three-way pipe is respectively connected to the second one-way valve and a third steam-using structure, and a third flow valve is also installed between the outlet of the second three-way pipe and the third steam-using structure.

[0021] By adopting this technical solution, the steam collected from the steam turbine by the steam collecting structure is divided into two parts, one of which is sent to the pressurizing structure, and the other is sent to the third-party steam-using structure. The steam in the third-party steam-using structure can be used for heating or condensation recovery. In this way, the steam in the steam turbine can be recovered and reused when the collected exhaust steam cannot be fully used or when the steam turbine is shut down for maintenance, providing another solution when the collected low-temperature and low-pressure steam does not need to be refluxed for reuse, which can further avoid energy waste.

[0022] Optionally, the steam turbine is further provided with a plurality of steam extraction ports, and the plurality of steam extraction ports are connected to the steam collecting end of the steam collecting structure through an insulated pipe.

[0023] By adopting this technical solution, when the steam pressure inside the steam turbine is too high and needs to be extracted and depressurized, the steam inside the steam turbine is released through the extraction port. At this time, the extraction port is connected to the steam collecting end of the steam collecting structure, and the exhaust steam discharged from the steam collecting structure and the steam outlet of the steam turbine is mixed and sent to the boosting structure to be recycled and reused. The low-temperature and low-pressure steam discharged from the steam turbine can be further recovered, thereby improving the recycling rate of the exhaust steam.

[0024] Optionally, a fourth flow valve is further provided between the plurality of steam extraction ports and the steam collecting end of the steam collecting structure.

[0025] By adopting this technical solution, the fourth flow valve can be used to control the flow rate of steam discharged from the steam extraction port on the steam turbine, and can accurately control the internal pressure of the steam turbine when discharging steam, ensuring that the steam turbine can operate stably and reducing maintenance efficiency.

[0026] Optionally, the pressurizing structure and the secondary pressurizing structure use a plurality of steam jet heat pumps connected in parallel to form a multi-channel pressurizing device.

[0027] By adopting this technical solution, multiple steam jet heat pumps can be connected in parallel to form a multi-channel boosting device, high-pressure steam can be ejected from multiple channels, and low-pressure steam can be injected with high-pressure steam, which is then mixed and output at a boosted pressure. Multi-channel injection of high-pressure steam can maintain stable operation when the steam flow fluctuates, achieving better energy-saving effects.

[0028] In summary, the present invention includes at least one of the following beneficial technical effects:

[0029] The low-temperature and low-pressure steam discharged from the steam outlet of the steam turbine is collected, and the temperature and pressure of the collected low-temperature and low-pressure steam are increased through a pressurized structure. When it reaches the use standard, the heated and pressurized steam is sent back to the steam inlet of the steam turbine through a reflux pipeline for reuse, omitting the process of condensing the exhausted steam and sending it back to the boiler for reheating, reducing the heat loss during condensation and effectively improving the energy recovery rate.

[0030] A two-stage pressurization structure is installed to send the steam that has been heated and pressurized by the first-stage pressurization structure to the space between the impellers at each stage for use, and the steam that has been heated and pressurized for the second time is sent back to the steam inlet end of the steam turbine for use. In this way, the steam that has been heated and pressurized can be used between the impellers at each stage and at the steam inlet end at the same time, thereby improving the utilization rate of the exhausted steam after heating and pressurization treatment.

[0031] A three-way pipeline is installed at the steam transmission end of the steam collecting structure to divide the steam collected from the steam turbine by the steam collecting structure into two parts, one part is sent to the pressurizing structure, and the other part is sent to the third-party steam-using structure. When the collected exhaust steam cannot be fully used or the steam turbine is shut down for maintenance, the steam in the steam turbine can be recovered and reused through the third-party steam-using structure, providing another solution when there is no need to return the collected low-temperature and low-pressure steam for reuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the utility model.

[0033] Explanation of the reference numerals in the accompanying drawings: 1. Steam turbine; 101. Steam inlet; 102. Steam outlet; 103. Secondary steam inlet; 104. Steam extraction port; 2. Steam collecting structure; 201. Steam collecting end; 202. Steam transmission end; 3. Pressurization structure; 31. Secondary pressurization structure; 4. Return line; 5. First three-way pipe; 51. Second three-way pipe; 6. Second non-return valve; 61. First non-return valve; 7. First flow valve; 72. Fourth flow valve; 71. Second flow valve; 73. Third flow valve; 8. Boiler; 9. Third steam structure. DETAILED DESCRIPTION

[0034] The following combination Figure 1 The utility model is described in further detail.

[0035] The utility model embodiment discloses a recirculating steam turbine structure. Figure 1 A reflux steam turbine structure mainly includes a steam turbine 1, a steam collecting structure 2 for collecting low-temperature and low-pressure steam discharged from the steam turbine, a pressurizing structure 3 for heating and pressurizing the low-temperature and low-pressure steam, a reflux pipeline 4 for returning the heated and pressurized steam to the steam turbine 1 for reuse, a one-way valve for controlling the flow direction of the steam, and a flow valve for controlling the steam flow.

[0036] Reference Figure 1The steam turbine 1 is provided with a steam inlet 101 at one end, a steam outlet 102 at the other end, a secondary steam inlet 103 and a steam extraction port 104 arranged between the impellers at each stage. The secondary steam inlet 103 between the impellers at each stage adopts a reheat steam turbine 1 scheme with a multi-stage design. Each stage of the impeller has a corresponding nozzle and a baffle. An interface for connecting an external high-pressure steam source is reserved between each stage. The steam inlet 101 is connected to the boiler 8. The boiler 8 delivers high-temperature and high-pressure steam into the steam turbine 1 through the steam inlet 101. At the same time, when the steam turbine 1 is running, combined with the operating conditions of the steam turbine 1, high-temperature and high-pressure steam is added to the secondary steam inlet 103 or part of the steam is discharged from the steam extraction port 104.

[0037] Reference Figure 1 The steam outlet end 102 of the steam turbine 1 is connected to the steam collecting end 201 of the steam collecting structure 2 through an insulated pipe, the fourth flow valve 72 is connected to the outside of the steam extraction port 104, the fourth flow valve 72 and the steam transmission end 202 of the steam collecting structure 2 are connected through an insulated pipe, the steam collecting structure 2 adopts a high-pressure fan to collect the exhausted steam uniformly, and discharges it from the other end of the fan and is connected to the steam transmission end 202 pipeline, the other end of the steam transmission end 202 pipeline is connected to the second three-way pipe 51, the other two outlets of the second three-way pipe 51 are respectively connected to the inlet of the third flow valve 73 and the inlet of the second non-return valve 6 through an insulated pipe, wherein the third flow valve 73 is connected to the third steam-using structure 9 through an insulated pipe, wherein the second non-return valve 6 is connected to the pressurized structure 3 through an insulated pipe. The exhaust steam discharged from the steam outlet end 102 of the steam turbine 1 is collected by the steam collecting end 201 of the steam collecting structure 2 and then output from the steam transmission end 202, and the output exhaust steam is divided into two parts through the second three-way pipe 51, one part flows to the third-party steam-using structure 9, and the other part flows into the pressurizing structure 3 through the second one-way valve 6; by dividing the exhaust steam collected by the steam collecting structure 2 into two parts, the steam in the steam turbine 1 can be recovered and reused through the third-party steam-using structure 9 when the collected exhaust steam cannot be fully used, thereby avoiding the problem of energy waste.

[0038] Reference Figure 1The pressurizing structure 3 is composed of multiple steam jet heat pumps connected in parallel. High-temperature driving steam and low-temperature low-pressure steam entering through the second one-way valve 6 are used in multiple channels and mixed after being output through multiple steam jet heat pumps, and connected to an interface of the first three-way pipe 5 through a pipeline. The other two interfaces of the first three-way pipe 5 are respectively connected to the inlet of the first flow valve 7 and the inlet of the first one-way valve 61 through an insulated pipeline, wherein the outlet of the first flow valve 7 is connected to the secondary steam inlet 103 of the turbine 1 through an insulated pipeline, wherein the outlet of the first one-way valve 61 is connected to the secondary pressurizing structure 31. The steam heated and pressurized by the pressurization structure 3 is divided into two parts through the first three-way pipe 5, one part of which returns to the secondary steam inlet 103 through the first flow valve 7 to replenish energy for the impellers of each stage of the turbine 1, and the other part enters the secondary pressurization structure 31 through the first one-way valve 61 for secondary heating and pressurization; in this way, the steam heated and pressurized by the pressurization structure 3 can be sent to between the impellers of each stage for use, and the steam heated and pressurized by the secondary heating and pressurization can be sent back to the steam inlet end 101 of the turbine 1 for use, and the steam after heating and pressurization can be flexibly distributed through the first flow valve 7 to improve the utilization rate of the steam reflux after heating and pressurization.

[0039] Reference Figure 1 The secondary pressurization structure 31 uses multiple steam jet heat pumps in parallel. In multiple channels, high-temperature driving steam and steam that has been heated and pressurized once and enters through the first one-way valve 61 are mixed by the steam jet heat pump and then output, and connected to the inlet of the second flow valve 71 through a pipeline. The outlet of the second flow valve 71 is connected to the steam inlet end 101 of the steam turbine 1 through an insulated pipeline. The steam that has been heated and pressurized twice by the secondary pressurization structure 31 flows back to the steam inlet end 101 of the steam turbine 1 through the control of the second flow valve 71 and mixes with the steam delivered from the boiler 8 before entering the steam turbine 1 for use; this process directly heats and pressurizes the recovered exhaust steam so that it can flow directly back to the steam inlet end 101 of the steam turbine 1 for use, reducing heat loss during condensation.

[0040] Reference Figure 1The implementation principle of the embodiment of the structure of a reflux steam turbine 1 of the utility model is as follows: the high-temperature and high-pressure steam generated in the boiler 8 enters the steam turbine 1 through the steam inlet end 101 of the steam turbine 1, and becomes low-energy low-temperature and low-pressure steam after being used by the steam turbine 1, and exits from the steam outlet end 102 of the steam turbine 1. At the same time, the steam turbine 1 will also extract part of the low-temperature and low-pressure steam from the steam extraction port 104 when in use, and the low-temperature and low-pressure steam will be collected by the steam collecting end 201 of the steam collecting structure 2 and output from the steam transmission end 202. The output low-temperature and low-pressure steam is divided into two parts after passing through the second three-way pipe 51, one part of which flows to the third party steam user. Structure 9, and the other part flows into the pressurizing structure 3 through the second one-way valve 6. The steam heated and pressurized by the pressurizing structure 3 is divided into two parts through the first three-way pipe 5. One part returns to the secondary steam inlet 103 through the first flow valve 7 to replenish energy for the impellers of each stage of the steam turbine 1, and the other part enters the secondary pressurizing structure 31 through the first one-way valve 61 for secondary heating and pressure increase. The steam that has undergone secondary heating and pressure increase flows back to the steam inlet end 101 of the steam turbine 1 through the second flow valve 71 and mixes with the steam delivered from the boiler 8 before entering the steam turbine 1 for use, thereby completing the entire steam reflux process.

[0041] Reference Figure 1 In the whole process, the step of condensing the collected exhaust steam into water and then sending it back to the boiler 8 for heating is omitted. The collected exhaust steam is directly heated and pressurized, and then the processed steam is returned to the steam turbine 1 for use, which reduces the heat loss during condensation and effectively improves the energy utilization rate. The steam is subjected to secondary treatment through the two-stage boosting structure, and the steam after heating and pressurization is distributed and adjusted through the three-way pipe and the flow valve, which can improve the utilization rate of the reflux steam. At the same time, a three-way pipe is installed at the steam transmission end 202 of the steam collecting structure 2 to connect to the third-party steam-using structure 9. When the collected exhaust steam cannot be completely refluxed, it can be recycled and reused through the third-party steam-using structure 9, thereby further improving the energy recovery rate.

[0042] The above are all preferred embodiments of the present utility model, and are not intended to limit the protection scope of the present utility model. Therefore, any equivalent changes made based on the structure, shape, and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A recirculating steam turbine structure, characterized in that: The invention comprises a steam turbine (1), a steam collecting structure (2), a pressurizing structure (3) and a return pipeline (4); the steam turbine (1) is provided with a steam inlet end (101) and a steam outlet end (102); the steam inlet end (101) on the steam turbine (1) is connected to a boiler (8); the steam collecting structure (2) comprises a steam collecting end (201) and a steam transmission end (202); the steam collecting end (201) is connected to the steam outlet end (102); the steam transmission end (202) is connected to the pressurizing structure (3); and the pressurizing structure (3) is connected to the steam inlet end (101) of the steam turbine (1) via a return pipeline (4).

2. A recirculating steam turbine structure according to claim 1, characterized in that: A secondary steam inlet (103) is arranged between each stage of the impeller of the steam turbine (1), and a first three-way pipe (5) is also arranged between the pressurizing structure (3) and the steam inlet end (101) of the steam turbine (1), one of the outlets of the first three-way pipe (5) is connected to the secondary steam inlet (103), the inlet of the first three-way pipe (5) is connected to the pressurizing structure (3), and the other outlet of the first three-way pipe (5) is connected to the steam inlet end (101) of the steam turbine (1).

3. A recirculating steam turbine structure according to claim 2, characterized in that: A first flow valve (7) is also provided between the first three-way pipe (5) and the secondary steam inlet (103).

4. A recirculating steam turbine structure according to claim 3, characterized in that: A secondary pressurizing structure (31) is also installed between the first three-way pipe (5) and the steam inlet end (101) of the steam turbine (1), and a first non-return valve (61) is also installed between the secondary pressurizing structure (31) and the first three-way pipe (5), wherein the installation direction of the first non-return valve (61) is such that the first three-way pipe (5) flows toward the secondary pressurizing structure (31).

5. A recirculating steam turbine structure according to claim 4, characterized in that: A second flow valve (71) is also provided between the secondary pressurizing structure (31) and the steam inlet end (101) of the steam turbine (1).

6. A recirculating steam turbine structure according to any one of claims 1 to 5, characterized in that: The steam transmission end (202) of the pressurizing structure (3) and the steam collecting structure (2) is also provided with a second one-way valve (6), and the installation direction of the second one-way valve (6) is such that the steam flows from the steam collecting structure (2) to the pressurizing structure (3).

7. A recirculating steam turbine structure according to claim 4 or 5, characterized in that: A second three-way pipe (51) is further provided between the steam delivery end (202) of the steam collecting structure (2) and the first one-way valve (61); the inlet of the second three-way pipe (51) is connected to the steam delivery end (202); the outlet of the second three-way pipe (51) is respectively connected to the first one-way valve (61) and a third steam supply structure (9); and a third flow valve (73) is further installed between the outlet of the second three-way pipe (51) and the third steam supply structure (9).

8. A recirculating steam turbine structure according to any one of claims 1 to 5, characterized in that: The steam turbine (1) is also provided with a plurality of steam extraction ports (104), and the plurality of steam extraction ports (104) are connected to the steam collecting end (201) of the steam collecting structure (2) via a heat-insulating pipe.

9. A recirculating steam turbine structure according to claim 8, characterized in that: A fourth flow valve (72) is also provided between the plurality of steam extraction ports (104) and the steam collecting end (201) of the steam collecting structure (2).

10. A recirculating steam turbine structure according to claim 4 or 5, characterized in that: The pressurizing structure (3) and the secondary pressurizing structure (31) use a plurality of steam jet heat pumps connected in parallel to form a multi-channel pressurizing device.

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