Steam supply system based on steam-electricity double-drive system of thermal power generating unit

Abstract

The utility model provides a steam supply system based on a steam-electricity double-drive system of a thermal power generating unit. According to the scheme, the steam supply system comprises a steam-electricity double-drive module, a medium-pressure industrial steam header and a low-pressure industrial steam header. A back pressure turbine steam source inlet of the steam-electricity double-drive module is connected with an intermediate reheater outlet of the boiler, and a steam exhaust port of a back pressure turbine is connected with a low-pressure industrial steam header; a steam extraction opening of the back pressure turbine is connected with a medium-pressure industrial steam header; wherein the low-pressure industrial steam header is respectively connected with an outlet of the intermediate reheater and a low-temperature reheat steam pipeline; the medium-pressure industrial steam header is connected with an outlet of the intermediate reheater and a low-temperature reheat steam pipeline. And the low-pressure industrial steam header and the medium-pressure industrial steam header are both connected with a load.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam supply, and in particular relates to a steam supply system based on a steam-electric dual-drive system of a thermal power unit. Background Art

[0002] The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] With the adjustment of energy structure and the vigorous promotion of centralized steam supply, thermal power units, as comprehensive energy supply bases, have gradually become an ideal source of steam supply. As a highly efficient heating technology for thermal power units, steam-electric dual-drive technology can achieve cascade utilization of steam energy, ensure the stability of steam supply, and improve the economic efficiency of the unit.

[0004] Steam-electric dual drive uses a back pressure machine to drive rotating machinery (induced draft fan, pump, etc.), exhausts steam from the back pressure machine, extracts steam, etc. to supply steam to the outside, and uses a generator to balance the power between the back pressure machine and the rotating machinery. However, the inventors found that when a back pressure machine fails or the exhaust volume does not match the user's steam demand, it will seriously affect the stability and safety of the heating system, and the existing solutions lack consideration of this situation. Utility Model Content

[0005] In order to solve the above-mentioned problems, the utility model provides a steam supply system based on a steam-electric dual-drive system of a thermal power unit. The scheme is based on a thermal power unit utilizing the steam-electric dual-drive technology, and rationally utilizes low-temperature reheat steam and intermediate reheat steam as steam sources to construct a steam supply system. On the one hand, the cascade utilization of steam is realized, and on the other hand, the stability and safety of the steam supply system are ensured when a back pressure machine fails or the exhaust volume does not match the user's steam demand.

[0006] A steam supply system based on a steam-electric dual-drive system of a thermal power unit, comprising a steam-electric dual-drive module, a medium-pressure industrial steam header and a low-pressure industrial steam header;

[0007] The steam source inlet of the back pressure machine of the steam-electric dual-drive module is connected to the outlet of the intermediate reheater of the boiler, and the exhaust port of the back pressure machine is connected to the low-pressure industrial steam manifold; the steam extraction port of the back pressure machine is connected to the medium-pressure industrial steam manifold;

[0008] Among them, the low-pressure industrial steam manifold is connected to the intermediate reheater outlet and the low-temperature reheat steam pipeline respectively; the medium-pressure industrial steam manifold is connected to the intermediate reheater outlet and the low-temperature reheat steam pipeline respectively; and the low-pressure industrial steam manifold and the medium-pressure industrial steam manifold are both connected to a load.

[0009] Furthermore, the steam output from the intermediate reheater outlet enters the low-pressure industrial steam header and the medium-pressure industrial steam header through two branches respectively; and both branches are provided with a temperature and pressure reducer.

[0010] Furthermore, the steam output from the low-temperature reheat steam pipeline enters the low-pressure industrial steam header and the medium-pressure industrial steam header through two branches, and both branches are provided with temperature and pressure reducers.

[0011] Furthermore, relevant shut-off valves and regulating valves are arranged in the pipeline of the steam supply system.

[0012] Furthermore, the steam-electric dual-drive module includes a back compressor and a generator.

[0013] Furthermore, the load is a steam demander, and the steam demander is connected to a low-pressure industrial steam manifold or a medium-pressure industrial steam manifold through a pipeline.

[0014] Furthermore, the steam demanders include low-pressure steam demanders and medium-pressure steam demanders.

[0015] Furthermore, the low-pressure industrial steam manifold of the steam supply system is connected to the low-pressure steam demander through a pipeline; the medium-pressure industrial steam manifold of the steam supply system is connected to the medium-pressure steam demander through a pipeline.

[0016] Furthermore, the low-pressure steam demanders include low-pressure industrial steam users outside the power plant, steam users within the power plant, deaerators and low-pressure heaters.

[0017] Furthermore, the medium-pressure steam demander is a medium-pressure industrial steam user outside the power plant.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] (1) The utility model provides a steam supply system based on a steam-electric dual-drive system of a thermal power unit. The scheme is based on a thermal power unit using the steam-electric dual-drive technology and rationally utilizes low-temperature reheat steam and intermediate reheat steam as steam sources to construct a steam supply system. On the one hand, it realizes the cascade utilization of steam. On the other hand, it ensures the stability and safety of the steam supply system when the back pressure machine fails or the exhaust volume does not match the user's steam demand.

[0020] (2) The solution described in the utility model can realize the steam source collection of medium and low pressure industrial steam and the steam distribution to industrial users through the medium and low pressure industrial steam manifolds.

[0021] (3) Based on the scheme described in the utility model, the balance between steam supply and steam use can be achieved through mutual backup of steam sources and mutual backup of users, thereby improving the reliability and safety of the system.

[0022] Advantages of additional aspects of the present invention will be partially given in the following description, and partially become apparent from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0024] Figure 1 It is a structural schematic diagram of a steam supply system based on a steam-electric dual-drive system of a thermal power unit described in an embodiment of the utility model;

[0025] Among them, 1. Low-pressure industrial steam manifold, 2. Medium-pressure industrial steam manifold, 3 to 32, shut-off valve, 33 to 35, check valve, 36 to 39, desuperheater and pressure reducer, 40, desuperheater, 41 to 42, regulating valve, 43 to 49, safety valve, 50 to 56, flow measuring device, 57, back pressure machine, 58, gearbox, 59, generator, 60, rotating machinery, 61, boiler, 62, intermediate reheat outlet steam, 63, low-temperature reheat steam, 64, medium-pressure industrial steam for external supply, 65, other reasonable steam sources, 66, various steam users in the plant area, 67, low-pressure industrial steam users outside the plant, 68, deaerator, 69, 5# low-pressure heater, 70, deaerator steam inlet pipeline, 71, 5# low-pressure heater steam inlet pipeline. DETAILED DESCRIPTION

[0026] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0027] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0029] In the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0030] like Figure 1 As shown, the steam supply system based on the steam-electric dual-drive system of the thermal power unit includes a steam-electric dual-drive module, a medium-pressure industrial steam header and a low-pressure industrial steam header;

[0031] The steam source inlet of the back pressure machine of the steam-electric dual-drive module is connected to the outlet of the intermediate reheater of the boiler 61, and the exhaust port of the back pressure machine is connected to the low-pressure industrial steam manifold; the steam extraction port of the back pressure machine is connected to the medium-pressure industrial steam manifold;

[0032] Among them, the low-pressure industrial steam manifold is connected to the intermediate reheater outlet and the low-temperature reheat steam pipeline respectively; the medium-pressure industrial steam manifold is connected to the intermediate reheater outlet and the low-temperature reheat steam pipeline respectively; and the low-pressure industrial steam manifold and the medium-pressure industrial steam manifold are both connected to a load.

[0033] In a specific implementation, the steam output from the intermediate reheater outlet enters the low-pressure industrial steam manifold and the medium-pressure industrial steam manifold respectively through two branches; and both branches are provided with a temperature reducer and pressure reducer; the steam output from the low-temperature reheat steam pipeline enters the low-pressure industrial steam manifold and the medium-pressure industrial steam manifold respectively through two branches, and both branches are provided with a temperature reducer and pressure reducer.

[0034] In a specific implementation, the steam 62 at the outlet of the intermediate reheater is used as the steam source for the back pressure machine, and the exhaust steam of the back pressure machine is sent to the low-pressure industrial steam manifold; the steam at the outlet of the intermediate reheater and the low-temperature reheated steam 63 are used as the backup steam source for the low-pressure industrial steam manifold through the temperature and pressure reducing device; at the same time, other reasonable steam sources 65 can be connected to the low-pressure industrial steam manifold.

[0035] The low-pressure industrial steam manifold provides steam to low-pressure industrial steam users 67 outside the factory, steam users 66 in the factory area, deaerator 68 and 5# low-pressure heater 69 (i.e., No. 5 low-pressure heater) through the piping system.

[0036] The intermediate extraction steam of the back pressure machine, the low-temperature reheat steam and the outlet steam of the intermediate reheater are supplied to the medium-pressure industrial steam manifold after being reduced in temperature and pressure; the medium-pressure industrial steam manifold realizes the supply of medium-pressure industrial steam 64 to the outside.

[0037] In a specific implementation, the steam-electric dual-drive module includes a back pressure machine 57 and a generator 59; a shut-off valve (i.e. Figure 1 3 to 32), check valve (i.e. Figure 1 33 to 35), temperature and pressure reducer (i.e. Figure 1 36 to 39), desuperheater 40, regulating valve (i.e. Figure 1 41 to 42 in the figure), a safety valve 49 and a flow measuring device (i.e. Figure 1 50 to 56).

[0038] In a specific implementation, the load is a steam demander, and the steam demander is connected to a low-pressure industrial steam manifold or a medium-pressure industrial steam manifold through a pipeline; the steam demander includes a low-pressure steam demander and a medium-pressure steam demander.

[0039] In a specific implementation, the low-pressure industrial steam manifold of the steam supply system is connected to the low-pressure steam demander through a pipeline; the medium-pressure industrial steam manifold of the steam supply system is connected to the medium-pressure steam demander through a pipeline.

[0040] In a specific implementation, the low-pressure steam demanders include low-pressure industrial steam users outside the power plant, steam users inside the power plant, deaerators and low-pressure heaters; the medium-pressure steam demanders are medium-pressure industrial steam users outside the power plant.

[0041] Specifically, for ease of understanding, the solution described in this embodiment is described in detail below in conjunction with the actual application of the system described in this embodiment:

[0042] (1) Utilization of low-pressure industrial steam

[0043] The steam at the outlet of the intermediate reheater is discharged to the low-pressure industrial steam header 1 after work through the back pressure machine 57, and provides steam to low-pressure industrial steam users outside the factory; at this time, the shut-off valves 3, 4, 8, 11 and 15 are opened.

[0044] When the exhaust steam of the back pressure machine is greater than the user's steam demand, steam is supplied to the deaerator, 5# low-pressure heater or various steam users in the plant, and the specific steam consumption is allocated according to the needs of each user; at this time, shut-off valves 3, 4, 8, 11 and 15 are opened, shut-off valves 12 to 21 and regulating valves 41 to 42 are opened according to the steam demand, and shut-off valves 18 and 21 are opened as backup when the regulating valve fails.

[0045] When the back pressure machine fails or the exhaust volume of the back pressure machine is less than the user's steam demand, the intermediate reheater outlet steam or the low-temperature reheat steam is supplemented after being cooled and reduced in pressure; at this time, the shut-off valves 3, 5, 6 and 11 and the temperature and pressure reducing device 36 in the intermediate reheater outlet steam pipeline are opened, or the shut-off valves 22, 23 and 10 and the temperature and pressure reducing device 39 in the low-temperature reheat steam pipeline are opened, and the shut-off valves 4 and 8 are opened as the back pressure machine runs.

[0046] (2) Utilization of medium-pressure industrial steam

[0047] The back pressure machine extracts steam to supply the medium-pressure industrial steam manifold 2, and supplies medium-pressure industrial steam to the outside; at this time, the shut-off valves 27, 28 and 32 are opened.

[0048] When the back pressure machine fails or the steam extraction of the back pressure machine is less than the user's steam demand, the intermediate reheater outlet steam or the low-temperature reheated steam is supplemented after being cooled and reduced in pressure; at this time, the shut-off valves 3, 29, 30 and 31 and the temperature and pressure reducing device 37 in the intermediate reheater outlet steam pipeline are opened or the shut-off valves 22, 24, 25 and 26 and the temperature and pressure reducing device 38 in the low-temperature reheat steam pipeline are opened, and the shut-off valves 27 and 28 are opened as the back pressure machine is running.

[0049] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. The steam supply system based on the steam-electric dual drive system of thermal power units is characterized by: Including steam-electric dual drive module, medium-pressure industrial steam header and low-pressure industrial steam header; The steam source inlet of the back pressure machine of the steam-electric dual-drive module is connected to the outlet of the intermediate reheater of the boiler, and the exhaust port of the back pressure machine is connected to the low-pressure industrial steam manifold; the steam extraction port of the back pressure machine is connected to the medium-pressure industrial steam manifold; Among them, the low-pressure industrial steam manifold is connected to the intermediate reheater outlet and the low-temperature reheat steam pipeline respectively; the medium-pressure industrial steam manifold is connected to the intermediate reheater outlet and the low-temperature reheat steam pipeline respectively; and the low-pressure industrial steam manifold and the medium-pressure industrial steam manifold are both connected to a load.

2. The steam supply system based on the steam-electric dual-drive system of a thermal power unit according to claim 1, characterized in that: The steam output from the intermediate reheater outlet enters the low-pressure industrial steam header and the medium-pressure industrial steam header through two branches respectively; and both branches are provided with a temperature and pressure reducer.

3. The steam supply system based on the steam-electric dual drive system of a thermal power unit according to claim 1, characterized in that: The steam output from the low-temperature reheat steam pipeline enters the low-pressure industrial steam header and the medium-pressure industrial steam header through two branches, and both branches are provided with temperature and pressure reducers.

4. The steam supply system based on the steam-electric dual drive system of a thermal power unit according to claim 1, characterized in that: The pipeline of the steam supply system is provided with a shut-off valve and a regulating valve.

5. The steam supply system based on the steam-electric dual drive system of a thermal power unit according to claim 1, characterized in that: The steam-electric dual-drive module includes a back compressor and a generator.

6. The steam supply system based on the steam-electric dual drive system of a thermal power unit according to claim 1, characterized in that: The load is a steam demander, and the steam demander is connected to a low-pressure industrial steam manifold or a medium-pressure industrial steam manifold through a pipeline.

7. The steam supply system based on the steam-electric dual drive system of a thermal power unit according to claim 6, characterized in that: The steam demanders include low-pressure steam demanders and medium-pressure steam demanders.

8. The steam supply system based on the steam-electric dual drive system of a thermal power unit according to claim 7, characterized in that: The low-pressure industrial steam manifold of the steam supply system is connected to the low-pressure steam demander through a pipeline; the medium-pressure industrial steam manifold of the steam supply system is connected to the medium-pressure steam demander through a pipeline.

9. The steam supply system based on the steam-electric dual drive system of a thermal power unit according to claim 7, characterized in that: The low-pressure steam demanders include low-pressure industrial steam users outside the power plant, steam users inside the power plant, deaerators and low-pressure heaters.

10. The steam supply system based on the steam-electric dual drive system of a thermal power unit according to claim 7, characterized in that: The medium-pressure steam demander is a medium-pressure industrial steam user outside a power plant.

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