Steam turbine and gas turbine dual drive steam supply system and steam supply method

Abstract

The application provides a steam and electricity dual-drive steam supply system and a steam supply method, and belongs to the technical field of steam supply. The system comprises a boiler, a steam power generation mechanism, a back pressure steam turbine and a motor. The steam power generation mechanism is connected with the reheated steam outlet end of the boiler at the steam inlet end, and is connected with the steam user end at the steam outlet end. The back pressure steam turbine is connected with the reheated steam outlet end of the boiler at the steam inlet end, and is connected with the steam user end at the steam outlet end. The output shaft of the back pressure steam turbine is connected with the motor and the compressor through a clutch. When the work power of the reheated steam is greater than the working power of the compressor, the back pressure steam turbine is used for driving the motor to generate electricity and driving the compressor to compress steam. The power generation end of the motor is connected with the auxiliary power and the power grid, and is used for transmitting the generated electric energy to the auxiliary power or the power grid. The application has the advantages of simple structure, flexible and efficient steam supply, reduced steam energy loss, and low steam supply cost.

Description

Technical Field

[0001] This invention relates to the field of steam supply technology, specifically to a steam-electric dual-drive steam supply system and a steam supply method. Background Technology

[0002] Cogeneration plants are thermal power plants that use combined heat and power (CHP) units to produce both electricity and heat. While generating electricity, they utilize the high-temperature, high-pressure steam from the turbine to supply steam and heat to users, and have become the main method for urban heating, industrial park heating, and industrial steam consumption. Currently, conventional steam supply methods for CHP plants include cold reheat, hot reheat, and intermediate exhaust steam supply. Cold reheat and hot reheat steam supply involve extracting steam from the cold and hot sections of the primary reheat unit. However, cold reheat and hot reheat steam supply need to consider the overheating problem of the boiler reheater, thus limiting the available steam volume. Furthermore, the hot reheat steam temperature is higher, requiring desuperheating to meet the supply demand, inevitably resulting in energy loss. During deep peak shaving of the unit, cold reheat and hot reheat steam supply methods need to be combined with technologies such as low-pressure cylinder cut-off, intermediate valve parameter regulation, and combined high and low pressure bypass steam extraction to ensure the stability of steam parameters and extraction volume, making the control method complex.

[0003] For thermal power plants, choosing a reliable steam supply method not only provides users with a stable supply of steam but also ensures the safe and stable operation of the unit, while fully utilizing the system's thermal energy and minimizing losses during energy conversion. Currently, most thermal power plants extract steam from the high-pressure steam section to meet user pressure parameters, then depressurize and reduce the pressure before supplying it to users. While this meets user needs, it wastes the energy of the high-pressure steam, resulting in energy loss and increased heating costs. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-drive steam-electric steam supply system. This system addresses the problem of power plants selecting to extract steam from the high-pressure steam section, depressurize and reduce its pressure, and then supply it to users in order to meet their steam demand. While this meets user needs, it wastes the energy of the high-pressure steam, resulting in energy loss and increased heating costs.

[0005] To achieve the above objectives, embodiments of the present invention provide a dual-drive steam supply system, the system comprising:

[0006] boiler;

[0007] A steam power generation mechanism, wherein the steam inlet of the steam power generation mechanism is connected to the reheat steam outlet of the boiler, the steam outlet of the steam power generation mechanism is connected to the steam inlet of the compressor, and the steam outlet of the compressor is connected to the steam user end;

[0008] A back-pressure steam turbine, wherein the steam inlet of the back-pressure steam turbine is connected to the reheat steam outlet of the boiler, the steam outlet of the back-pressure steam turbine is connected to the steam user end, and the output shaft of the back-pressure steam turbine is connected to a motor and a compressor via a clutch. The back-pressure steam turbine is used to drive the motor to generate electricity and drive the compressor to compress steam when the power of the reheat steam is greater than the working power of the compressor.

[0009] The generator end of the motor is connected to the plant's power supply and the power grid, and is used to transmit electrical energy to the plant's power supply or the power grid.

[0010] Optionally, the output shaft of the motor is connected to the compressor, and is used to drive the compressor to compress steam together with the back pressure turbine when the power output of the back pressure turbine using reheat steam is less than the working power of the compressor, using plant power or grid power.

[0011] The motor is also used to drive the compressor to compress steam when the back pressure turbine is shut down.

[0012] Optionally, the steam power generation mechanism includes:

[0013] Medium-pressure cylinders and low-pressure cylinders;

[0014] The steam inlet of the intermediate-pressure cylinder is connected to the reheat steam outlet of the boiler, and the steam outlet of the intermediate-pressure cylinder is connected to the steam inlet of the compressor and the steam inlet of the low-pressure cylinder. The intermediate-pressure cylinder is used to supply steam to the compressor and the boiler.

[0015] Optionally, the steam outlet of the low-pressure cylinder is connected to the boiler via a boiler steam-water system.

[0016] Optionally, the boiler steam-water system includes:

[0017] The condenser, condensate pump, cryogenic heater, deaerator, feedwater pump, and high-temperature heater are arranged sequentially along the direction of medium flow.

[0018] The condenser is connected to the steam outlet of the low-pressure cylinder, and the water outlet of the high-temperature heater is connected to the water inlet of the boiler.

[0019] Optionally, the steam outlet of the compressor and the steam outlet of the back-pressure turbine are connected to the steam user end through a steam distributor cylinder, which is used to distribute steam to the steam user end through corresponding pipelines.

[0020] Optionally, the reheat steam outlet of the boiler and the steam outlet of the intermediate pressure cylinder are both connected to the steam inlet of the steam distributor, for supplying steam to the steam user through the steam distributor.

[0021] A second aspect of the present invention provides a steam supply method applied to the aforementioned dual-drive steam-electric steam supply system, the method comprising:

[0022] Obtain the steam pressure demand value at the steam user end and the steam pressure value at the outlet end of the intermediate pressure cylinder;

[0023] Based on the steam pressure demand value at the steam user end and the steam pressure value at the outlet end of the intermediate pressure cylinder, a steam supply strategy is determined.

[0024] Based on the aforementioned steam supply strategy, steam is supplied to steam users.

[0025] Optionally, the steam supply strategy includes:

[0026] Determine whether the steam pressure at the outlet of the intermediate pressure cylinder is greater than the required steam pressure.

[0027] If yes, the steam outlet of the intermediate pressure cylinder is controlled to directly supply steam to the steam distribution cylinder. If no, the back pressure turbine, clutch, motor and compressor are started, and the steam outlet of the intermediate pressure cylinder is controlled to supply steam to the compressor to increase the pressure of the steam discharged from the intermediate pressure cylinder. The compressor increases the steam pressure to the required steam pressure value, and the back pressure turbine discharge is automatically adjusted to the required steam pressure value. The steam discharged from the compressor and the back pressure turbine together supply steam to the steam distribution cylinder. The steam driven by the back pressure turbine comes from the steam inlet of the intermediate pressure cylinder.

[0028] Optionally, the method further includes:

[0029] During the operation of the compressor:

[0030] If the power output of the back-pressure steam turbine using reheated steam is greater than the operating power of the compressor, then the drive motor generates electricity;

[0031] If the power output of the back-pressure turbine using reheated steam is less than the operating power of the compressor, the motor and the back-pressure turbine are controlled to jointly drive the compressor.

[0032] This technical solution utilizes a back-pressure steam turbine to perform work on steam, which is then delivered to the steam user. Simultaneously, the back-pressure steam turbine drives a compressor to compress low-pressure steam supplied by a steam power generation unit, thus achieving steam supply. The system has a simple structure and offers advantages such as flexible and efficient steam supply, further reducing steam energy loss and lowering steam supply costs. Furthermore, when the back-pressure steam turbine is performing work, excess energy is used to drive a motor to generate electricity, reducing plant power consumption and further decreasing production costs.

[0033] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0034] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0035] Figure 1 This is a schematic diagram of the structure of the first dual-drive steam supply system provided by the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of the second type of dual-drive steam supply system provided by the present invention;

[0037] Figure 3 This is a flowchart of the steam supply method provided by the present invention;

[0038] Figure 4 This is an overall flowchart of the steam supply method provided by the present invention.

[0039] Explanation of reference numerals in the attached figures

[0040] 1- Boiler; 2- Steam power generation mechanism; 3- Compressor;

[0041] 4-Steam user end; 5-Back pressure turbine; 6-Clutch;

[0042] 7-Motor; 8-Steam distributor; 9-Boiler steam-water system;

[0043] 21 - Medium-pressure cylinder; 22 - Low-pressure cylinder; 71 - Power grid;

[0044] 91-Condenser; 92-Condensate pump; 93-Cryogenic heater;

[0045] 94-Deaerator; 95-Feed water pump; 96-High temperature heater;

[0046] 101-Valve. Detailed Implementation

[0047] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0048] In the embodiments of the present invention, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use.

[0049] The terms “first,” “second,” “third,” etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0050] The terms "parallel" and "perpendicular" do not mean that the components must be absolutely parallel or perpendicular, but rather that they can be slightly tilted. For example, "parallel" simply means that its direction is more parallel than "perpendicular," not that the structure must be completely parallel, but that it can be slightly tilted.

[0051] The terms "horizontal," "vertical," and "sag" do not imply that a component must be absolutely horizontal, vertical, or sagging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0052] Furthermore, terms like "roughly" and "basically" are used to indicate that the content does not require absolute precision, but rather allows for a certain degree of deviation. For example, "roughly equal" does not simply mean absolute equality; in actual production and operation, achieving absolute "equality" is difficult, and a certain degree of deviation is generally present. Therefore, besides absolute equality, "roughly equal to" also includes the aforementioned situation where a certain degree of deviation exists. Using this as an example, in other cases, unless otherwise specified, terms like "roughly" and "basically" have similar meanings.

[0053] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] Figure 1 This is a schematic diagram of the structure of the first dual-drive steam supply system provided by the present invention; Figure 2 This is a schematic diagram of the structure of the second type of dual-drive steam supply system provided by the present invention; Figure 3 This is a flowchart of the steam supply method provided by the present invention; Figure 4 This is an overall flowchart of the steam supply method provided by the present invention.

[0055] Example 1

[0056] like Figure 1-4 As shown, this embodiment provides a dual-drive steam and electric steam supply system, the system comprising:

[0057] Boiler 1;

[0058] Steam power generation mechanism 2, the steam inlet of the steam power generation mechanism 2 is connected to the reheat steam outlet of the boiler 1, the steam outlet of the steam power generation mechanism 2 is connected to the steam inlet of the compressor 3, and the steam outlet of the compressor 3 is connected to the steam user terminal 4.

[0059] A back-pressure steam turbine 5 is provided, with its inlet end connected to the reheat steam outlet end of the boiler 1 and its outlet end connected to the steam user end 4. The output shaft of the back-pressure steam turbine 5 is connected to a motor 7 and a compressor 3 via a clutch 6. The back-pressure steam turbine 5 is used to drive the motor 7 to generate electricity and drive the compressor 3 to compress steam when the power output of the reheat steam is greater than the working power of the compressor 3.

[0060] The generator end of the motor 7 is connected to the plant power supply or the power grid 71 to transmit the generated electrical energy to the plant power supply or the power grid 71.

[0061] Specifically, in this embodiment, the steam discharged from the steam power generation unit 2 is compressed by the compressor 3 and then delivered to the steam user end 4, which can further meet the needs of users with higher pressure parameters. The system has a simple structure, flexible and efficient steam supply, and can further reduce the energy loss of steam and reduce the cost of steam supply. At the same time, when the back pressure turbine is working, the excess energy is used to drive the motor to generate electricity, reducing the plant's electricity consumption and further reducing production costs.

[0062] Since the amount of reheat steam may vary with the boiler load, the power output of the back-pressure turbine 5 may fluctuate. At the same time, the power output of the compressor 3 during the steam compression process will also vary due to the different steam consumption at the steam user end 4. Therefore, there may be a situation where the power output of the back-pressure turbine 5 using reheat steam is greater than the operating power of the compressor 3. In this case, the back-pressure turbine 5 converts the excess power into the drive motor 7 to generate electricity, and transmits the generated electricity to the power grid 71 as plant power, thereby reducing the power consumption of the power grid and reducing the cost of power generation and steam supply.

[0063] Furthermore, the output shaft of the motor 7 is connected to the compressor 3, and is used to power the compressor 3 with the power grid 71 when the power output of the back pressure turbine 5 using reheat steam is less than the working power of the compressor 3.

[0064] The motor 7 is also used to drive the compressor 3 to compress steam when the back pressure turbine 5 is shut down.

[0065] Specifically, since the amount of reheat steam may vary with the boiler load, the power output of the back-pressure turbine 5 may fluctuate. At the same time, the power output of the compressor 3 during the steam compression process will also vary due to the different steam consumption at the steam user end 4. Therefore, there may be a situation where the power output of the back-pressure turbine 5 using reheat steam is less than the operating power of the compressor 3. In this case, the plant power or the power grid 71 is used to supply power to the motor 7. The motor 7 and the back-pressure turbine 5 jointly drive the compressor 3 to compress steam to meet the steam consumption of the steam user end 4.

[0066] In another embodiment, when the back-pressure turbine 5 is shut down, the back-pressure turbine 5 can be disengaged via the clutch 6, and the compressor 3 can be driven entirely by the motor 7 to compress steam. The connection structure between the drive shaft of the back-pressure turbine 5, the shaft of the motor 7, and the compressor 3 via the clutch 6 is a conventional technique known to those skilled in the art and will not be described in detail here.

[0067] To address the issue of motor 7's shutdown affecting compressor 3's operation, another solution is proposed: motor 7 can be positioned at the exhaust end of compressor 3, while a clutch is placed between motor 7 and compressor 3 to release motor shutdown.

[0068] Furthermore, the steam power generation mechanism 2 includes:

[0069] Medium-pressure cylinder 21 and low-pressure cylinder 22;

[0070] The steam inlet of the intermediate pressure cylinder 21 is connected to the reheat steam outlet of the boiler 1, and the steam outlet of the intermediate pressure cylinder 21 is connected to the steam inlet of the compressor 3 and the steam inlet of the low pressure cylinder 22. The intermediate pressure cylinder 21 is used to supply steam to the compressor 3 and the low pressure cylinder 22.

[0071] Specifically, in this embodiment, the steam outlet of the intermediate pressure cylinder 21 is connected to the compressor 3. The exhaust steam of the intermediate pressure cylinder 21 has a certain pressure. The compressor 3 obtains steam that meets the requirements by compressing the exhaust steam of the intermediate pressure cylinder 21, which can reduce the working energy consumption of the compressor 3 and thus reduce the heating cost.

[0072] Furthermore, in another embodiment, the steam outlet of the low-pressure cylinder 22 is connected to the boiler 1 via the boiler steam-water system 9.

[0073] Specifically, the boiler steam-water system 9 includes:

[0074] The following components are arranged sequentially along the direction of medium flow: condenser 91, condensate pump 92, cryogenic heater 93, deaerator 94, feedwater pump 95, and high-temperature heater 96.

[0075] The condenser 91 is connected to the steam outlet of the low-pressure cylinder 22, and the water outlet of the high-temperature heater 96 is connected to the water inlet of the boiler 1.

[0076] Specifically, in this embodiment, the primary steam of the boiler first enters the high-pressure cylinder to do work. After doing work, the steam re-enters the boiler and is heated into reheat steam, which is then sent to the intermediate-pressure cylinder 3 to do work. The exhaust steam from the intermediate-pressure cylinder 3 enters the low-pressure cylinder 4 to do work, and the exhaust steam from the low-pressure cylinder 4 enters the condenser 91 to condense. The condensate is pumped by the condensate pump 92, then enters the low-temperature heater 93, and then enters the deaerator 95. Finally, the feedwater pump 94 pressurizes the steam and sends it to the high-pressure heater 96, where it enters the boiler 1 to be heated. After becoming high-temperature steam, it enters the high-pressure cylinder 2 to continue doing work, thus completing the boiler's thermal cycle.

[0077] In another embodiment, the steam outlet of the compressor 3 and the steam outlet of the back pressure turbine 5 are connected to the steam user terminal 4 through a steam distributor 8, which is used to distribute steam to the steam user terminal 4 through corresponding pipelines.

[0078] Specifically, the steam user terminal 4 can be configured as multiple independent steam user terminals. Each steam user terminal is connected to the steam outlet of the steam distribution cylinder 8 via a steam delivery pipeline. Each steam delivery pipeline is equipped with a flow meter, a pressure gauge, and a valve. The flow meter can obtain the steam flow rate on each steam delivery pipeline; the pressure gauge can obtain the steam pressure value on the corresponding pipeline, thereby accurately obtaining the steam pressure value in the steam delivery pipeline, realizing pressure monitoring, and improving safety; the opening and closing of the valve can control the flow rate, and simultaneously achieve accurate control of steam flow rate and fine adjustment of steam pressure.

[0079] The working pressure of the steam separator 8 can reach up to 16MPa, improving the safety of use.

[0080] In another embodiment, the reheat steam outlet of the boiler 1, the steam outlet of the intermediate pressure cylinder 21, and the steam outlet of the low pressure cylinder 22 are all connected to the steam inlet of the steam distributor 8, for supplying steam to the steam user end 4 through the steam distributor 8.

[0081] Specifically, in this embodiment, the reheat steam outlet of boiler 1, the steam outlet of intermediate pressure cylinder 21, and the steam outlet of low pressure cylinder 22 are all connected to the steam inlet of steam distributor 8, which allows for direct steam supply, improves steam utilization efficiency, and enhances the overall flexibility of the system.

[0082] More specifically, in this embodiment, valves 101 are provided on the steam transmission pipelines between the reheat steam outlet of boiler 1 and the steam inlet of back pressure turbine 5, between the reheat steam outlet of boiler 1 and the steam inlet of steam distributor 8, between the steam outlet of back pressure turbine 5 and the steam inlet of steam distributor 8, between the steam outlet of intermediate pressure cylinder 21 and the steam inlet of steam distributor 8, between the steam outlet of intermediate pressure cylinder 21 and the steam inlet of compressor 3, and between the steam outlet of low pressure cylinder 22 and the steam inlet of compressor 3. The valves 101 provided on the corresponding steam transmission pipelines are used to control the opening and closing of the corresponding pipelines.

[0083] Example 2

[0084] like Figure 3 As shown, the present invention also provides a steam supply method, applied to the above-mentioned dual-drive steam-electric steam supply system, the method comprising:

[0085] Step 101: Obtain the steam pressure demand value at the steam user end and the steam pressure value at the outlet end of the intermediate pressure cylinder;

[0086] Step 102: Determine the steam supply strategy based on the steam pressure demand value at the steam user end and the steam pressure value at the outlet end of the intermediate pressure cylinder;

[0087] Step 103: Based on the steam supply strategy, provide steam to the steam user.

[0088] Specifically, such as Figure 4 As shown, in this embodiment, the steam supply strategy includes:

[0089] Determine whether the steam pressure at the outlet of the intermediate pressure cylinder is greater than the required steam pressure.

[0090] If yes, the steam outlet of the intermediate pressure cylinder is controlled to directly supply steam to the steam distribution cylinder. If no, the back pressure turbine, clutch, motor and compressor are started, and the steam outlet of the intermediate pressure cylinder is controlled to supply steam to the compressor to increase the pressure of the steam discharged from the intermediate pressure cylinder. The compressor increases the steam pressure to the required steam pressure value, and the back pressure turbine discharge is automatically adjusted to the required steam pressure value. The steam discharged from the compressor and the back pressure turbine together supply steam to the steam distribution cylinder. The steam driven by the back pressure turbine comes from the steam inlet of the intermediate pressure cylinder.

[0091] In another implementation, the method includes:

[0092] Determine whether the steam pressure at the outlet of the intermediate pressure cylinder is greater than the required steam pressure.

[0093] If yes, then control the steam outlet of the intermediate pressure cylinder to supply steam to the steam distribution cylinder; if no, then determine whether the theoretical steam value at the steam outlet when the back pressure turbine is in working condition is greater than or equal to the steam pressure requirement value.

[0094] If yes, then control the steam outlet of the back-pressure turbine to supply steam to the steam distribution cylinder, and control the steam outlet of the intermediate-pressure cylinder to supply steam to the compressor, while controlling the back-pressure turbine to drive the compressor to compress steam to supply steam to the steam distribution cylinder; if no, then control the reheat steam outlet of the boiler to supply steam to the steam distribution cylinder.

[0095] Specifically, the opening and closing of the valves installed on the steam delivery pipeline can be controlled to switch the steam supply strategy and change the steam path to the compressor and steam distribution cylinder.

[0096] Furthermore, the method also includes:

[0097] During the operation of the compressor:

[0098] If the power output of the back-pressure steam turbine using reheated steam is greater than the operating power of the compressor, then the drive motor generates electricity;

[0099] If the power output of the back-pressure turbine using reheated steam is less than the operating power of the compressor, the motor and the back-pressure turbine are controlled to jointly drive the compressor.

[0100] In this solution, steam within the system is used as the driving force, supplemented by electricity, to drive the compressor to perform work, thereby increasing the steam pressure to meet the steam parameters required by the user. Furthermore, the steam used as the driving force can be reused in the system after performing work.

[0101] Example 3

[0102] In this embodiment, taking a 600MW cogeneration unit as an example, the steam pressure demand at the steam user end is 1.1 MPa. During normal power generation, the steam pressure at the boiler's reheat steam outlet is 3.03 MPa. After the steam passes through the intermediate pressure turbine to generate electricity, the steam pressure at the intermediate pressure turbine outlet is 0.64 MPa. At this point, the steam pressure at the intermediate pressure turbine outlet is less than the steam pressure demand at the steam user end. Therefore, it is necessary to use a compressor to compress the steam to increase the overall steam pressure. The theoretical steam pressure at the outlet of the back-pressure turbine when it is in operation is 1.1 MPa, which is equal to the steam pressure demand. Therefore, the back-pressure turbine can directly supply steam to the steam user end, and the back-pressure turbine can drive the compressor to compress the steam, reducing the pressure of the steam delivered from the intermediate pressure turbine outlet to the compressor to 1.1 MPa. The compressed steam is then mixed with the steam directly supplied by the back-pressure turbine and distributed to the steam user end by the steam distributor.

[0103] This solution selects a steam-electric dual-drive compressor for the booster configuration, using reheat steam for drive, which reduces the use of electricity and greatly saves energy; and the exhaust steam after the reheat steam has done work enters the steam distribution cylinder, and is then distributed to users through the steam distribution cylinder, which achieves the effect of energy saving.

[0104] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0105] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0106] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0107] Furthermore, various different implementations of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed in the present invention.

Claims

1. A dual-drive steam-electric steam supply system, characterized in that, The system includes: Boiler (1); Steam power generation mechanism (2), the steam inlet of the steam power generation mechanism (2) is connected to the reheat steam outlet of the boiler (1), the steam outlet of the steam power generation mechanism (2) is connected to the steam inlet of the compressor (3), and the steam outlet of the compressor (3) is connected to the steam user end (4). A back-pressure steam turbine (5) is provided. The steam inlet of the back-pressure steam turbine (5) is connected to the reheat steam outlet of the boiler (1). The steam outlet of the back-pressure steam turbine (5) is connected to the steam user end (4). The output shaft of the back-pressure steam turbine (5) is connected to the motor (7) and the compressor (3) through the clutch (6). The back-pressure steam turbine (5) is used to drive the motor (7) to generate electricity and drive the compressor (3) to compress steam when the power of the reheat steam is greater than the working power of the compressor (3). The generator end of the motor (7) is connected to the plant power and the power grid (71) to transmit electrical energy to the plant power or the power grid (71). The output shaft of the motor (7) is connected to the compressor (3) and is used to power the compressor (3) with plant power or grid (71) when the power of the back pressure turbine (5) using reheat steam is less than the working power of the compressor (3). The compressor (3) is driven by the back pressure turbine (5) to compress steam. The motor (7) is also used to drive the compressor (3) to compress steam when the back pressure turbine (5) is shut down.

2. The dual-drive steam supply system according to claim 1, characterized in that, The steam power generation mechanism (2) includes: Medium-pressure cylinder (21) and low-pressure cylinder (22); The steam inlet of the intermediate pressure cylinder (21) is connected to the reheat steam outlet of the boiler (1), and the steam outlet of the intermediate pressure cylinder (21) is connected to the steam inlet of the compressor (3) and the steam inlet of the low pressure cylinder (22). The intermediate pressure cylinder (21) is used to supply steam to the compressor (3) and the low pressure cylinder (22).

3. The dual-drive steam supply system according to claim 2, characterized in that, The steam outlet of the low-pressure cylinder (22) is connected to the boiler (1) through the boiler steam-water system (9).

4. The dual-drive steam supply system according to claim 3, characterized in that, The boiler steam-water system (9) includes: A condenser (91), a condensate pump (92), a cryogenic heater (93), a deaerator (94), a feed water pump (95), and a high-temperature heater (96) are arranged sequentially along the direction of medium flow. The condenser (91) is connected to the steam outlet of the low-pressure cylinder (22), and the water outlet of the high-temperature heater (96) is connected to the water inlet of the boiler (1).

5. The dual-drive steam supply system according to claim 1, characterized in that, The steam outlet of the compressor (3) and the steam outlet of the back pressure turbine (5) are connected to the steam user end (4) through a steam distributor (8). The steam distributor (8) is used to distribute steam to the steam user end (4) through the corresponding pipeline.

6. The dual-drive steam supply system according to claim 5, characterized in that, The reheat steam outlet of the boiler (1) and the steam outlet of the intermediate pressure cylinder (21) are both connected to the steam inlet of the steam distributor (8) for supplying steam to the steam user (4) through the steam distributor (8).

7. A steam supply method, applied to the steam-electric dual-drive steam supply system according to any one of claims 1-6, characterized in that, The method includes: Obtain the steam pressure demand value at the steam user end and the steam pressure value at the outlet end of the intermediate pressure cylinder; Based on the steam pressure demand value at the steam user end and the steam pressure value at the outlet end of the intermediate pressure cylinder, a steam supply strategy is determined. Based on the aforementioned steam supply strategy, steam is supplied to steam users.

8. The steam supply method according to claim 7, characterized in that, The steam supply strategy includes: Determine whether the steam pressure at the outlet of the intermediate pressure cylinder is greater than the required steam pressure. If yes, then the steam outlet of the intermediate pressure cylinder is controlled to supply steam to the steam distribution cylinder; if no, then the back pressure turbine, clutch, motor and compressor are started, and at the same time the steam outlet of the intermediate pressure cylinder is controlled to supply steam to the compressor to increase the pressure of the steam discharged from the intermediate pressure cylinder. The compressor increases the steam pressure to the required steam pressure value, and the back pressure turbine discharge is automatically adjusted to the required steam pressure value. The steam discharged from the compressor and the steam discharged from the back pressure turbine together supply steam to the steam distribution cylinder. The steam driven by the back pressure turbine comes from the steam inlet of the intermediate pressure cylinder.

9. The steam supply method according to claim 8, characterized in that, The method further includes: During the operation of the compressor: If the power output of the back-pressure steam turbine using reheated steam is greater than the operating power of the compressor, then the drive motor generates electricity; If the power output of the back-pressure turbine using reheated steam is less than the operating power of the compressor, the motor and the back-pressure turbine are controlled to jointly drive the compressor.

Images