Wide load steam supply system of high side coupling pressure matching device and working method

Abstract

The present application belongs to the technical field of combined heat and power, and discloses a wide-load steam supply system of high-side coupling pressure adapter and a working method. When the load is high, the unit supplies steam to the heat user normally by adjusting the medium-pressure cylinder. When the load is low, the unit uses the pressure adapter to inject low-pressure steam with high-pressure steam. The present application can solve the problem of insufficient steam supply or steam pressure when the heat supply unit rotates the baffle for low-load operation. By switching the steam source between high and low loads, the heat supply unit can run in a wide load range, meet the peak shaving demand of the power grid, create a new profit growth point for the enterprise, and improve the stability of steam supply. The present application has small modification range, low investment cost, high operation reliability, and is beneficial to further popularization and application.

Description

Technical Field

[0001] This invention belongs to the field of combined heat and power technology, specifically relating to a wide-load steam supply system and its working method with a high bypass coupling pressure matching device. Background Technology

[0002] Industrial steam supply by power generation companies is a type of combined heat and power (CHP), a highly efficient energy production method that combines the supply of heat and electricity. Comparing coal-fired CHP with separate heat and power generation, to produce the same amount of heat and electricity, CHP can save about 30% of coal compared to separate heat and power generation, and the overall efficiency can be increased from 50% to 75%.

[0003] Industrial steam supply system upgrades for thermal power plants are primarily based on user needs. Rotary diaphragm steam supply is currently a widely used method. This system controls steam flow and pressure by adjusting the opening of diaphragms in the steam pipeline, converting thermal energy into kinetic energy. By continuously adjusting the diaphragm opening, the control system maintains stable steam pressure and flow, ensuring that heat users consistently receive the required steam extraction pressure. However, due to limitations imposed by unit operating conditions, while the steam supply may meet user needs at high loads, the pressure and flow rate may not be sufficient during medium and low load operations. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a wide-load steam supply system and operating method with a high-side-coupling pressure matcher. Under high load, the unit supplies steam normally by adjusting the opening of the rotating diaphragm. Under medium and low load, a pressure matcher is added to use high-pressure steam to siphon low-pressure steam to meet the user's needs, thus realizing the wide-load steam supply requirements of the unit and ensuring the stability of steam supply. This solution has a small scope of modification and low investment, which is conducive to further promotion.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a wide-load steam supply system with a high-bypass coupling pressure matcher, comprising a boiler, wherein the boiler superheater outlet is connected to a high-pressure cylinder via a main steam pipeline, the boiler reheater outlet is connected to an intermediate-pressure cylinder, the low-pressure steam supply pipeline of the intermediate-pressure cylinder is connected to a pressure matcher and a heat user, the high-pressure steam supply bypass of the boiler main steam pipeline is connected to the pressure matcher, the pressure matcher is connected to the heat user, and the pressure matcher is connected to a desuperheating water system.

[0007] A further improvement of the present invention is that a first electric valve, a high-pressure bypass valve, and a third electric valve are provided on the high-pressure steam supply bypass of the boiler.

[0008] A further improvement of the present invention is that a fourth electric valve, a regulating valve, and a second check valve are provided on the low-pressure steam supply line of the intermediate-pressure cylinder.

[0009] A further improvement of the present invention is that a fifth electric valve is provided on the connection line between the low-pressure steam supply line of the intermediate-pressure cylinder and the pressure matching device.

[0010] A further improvement of the present invention is that a sixth electric valve is provided on the connection pipeline between the low-pressure steam supply pipeline of the intermediate-pressure cylinder and the heat user.

[0011] A further improvement of the present invention is that a seventh electric valve is provided on the connection pipeline between the pressure matcher and the heat user.

[0012] A further improvement of the present invention is that the desuperheating water system includes a pipeline connected to the water supply, and the pipeline connected to the water supply is equipped with a desuperheating water electric valve, a desuperheating water regulating valve and a first check valve.

[0013] Secondly, the present invention provides a method for operating a wide-load steam supply system with a high bypass coupling pressure matcher, including a conventional steam supply mode and a high bypass injection low-pressure steam heating mode.

[0014] The working method of the conventional steam supply mode is as follows:

[0015] The reheated steam from the boiler is sent into the intermediate-pressure cylinder to perform work;

[0016] The intermediate-pressure cylinder adjusts the steam supply to provide steam to heat users;

[0017] The operating method of the high-pressure side-ejector low-pressure steam heating mode is as follows:

[0018] The reheated steam from the boiler is sent into the intermediate-pressure cylinder to perform work;

[0019] The steam supply to the intermediate pressure cylinder is sent into the pressure matching device;

[0020] The main steam and desuperheating water from the boiler are fed into the pressure matching device;

[0021] The pressure matching device adjusts the pressure of the steam supply from the intermediate pressure cylinder, the main steam from the boiler, and the desuperheating water to supply steam to heat users.

[0022] A further improvement of the present invention is that a fifth electric valve is provided on the connection pipeline between the low-pressure steam supply pipeline of the intermediate-pressure cylinder and the pressure matching device, and a sixth electric valve is provided on the connection pipeline between the low-pressure steam supply pipeline of the intermediate-pressure cylinder and the heat user.

[0023] In normal steam supply mode, the fifth electric valve is in the closed state and the sixth electric valve is in the open state.

[0024] A further improvement of the present invention is that a fifth electric valve is provided on the connection pipeline between the low-pressure steam supply pipeline of the intermediate-pressure cylinder and the pressure matching device, a sixth electric valve is provided on the connection pipeline between the low-pressure steam supply pipeline of the intermediate-pressure cylinder and the heat user, a first electric valve, a high-pressure bypass valve and a third electric valve are provided on the high-pressure steam supply bypass of the boiler, the desuperheating water system includes a pipeline connected to the feed water, a desuperheating water electric valve, a desuperheating water regulating valve and a first check valve are provided on the pipeline connected to the feed water, and a seventh electric valve is provided on the connection pipeline between the pressure matching device and the heat user.

[0025] In the high-pressure bypass low-pressure steam heating mode, the first electric valve, the high-pressure bypass valve, the third electric valve, the desuperheating water electric valve, the desuperheating water regulating valve, the first check valve, the fifth electric valve, and the seventh electric valve are in the open state, and the sixth electric valve is in the closed state.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention enables the unit to supply normal steam to heat users under high load by adjusting the intermediate-pressure cylinder. During medium- and low-load operation, a pressure matching device is added to use high-pressure steam to induce low-pressure steam. This invention effectively addresses situations where the steam supply volume or pressure is insufficient during low-load operation of the heating unit's rotating diaphragm steam supply. By switching the steam source between high and low loads, it not only achieves wide-load operation of the heating unit, meeting the peak-shaving needs of the power grid and creating new profit growth points for enterprises, but also improves the stability of steam supply. This invention has a small modification scope, low investment cost, and high operational reliability, making it suitable for further promotion and application.

[0028] The method of this invention includes two modes: a conventional steam supply mode and a high-pressure bypass injection low-pressure steam heating mode. The appropriate mode can be flexibly selected according to specific needs, adapting to different working conditions and improving the system's adaptability and flexibility. In the conventional steam supply mode, reheated steam from the boiler is directly fed into the intermediate-pressure cylinder to perform work, and then the intermediate-pressure cylinder supplies steam to the heat user, ensuring efficient energy utilization. In the high-pressure bypass injection low-pressure steam heating mode, the pressure matching device regulates the pressure of the intermediate-pressure cylinder's steam supply, the boiler's main steam, and the desuperheating water, ensuring the supply pressure is stable and meeting the heat user's demand for steam at different pressures, thus improving the stability and reliability of the heating system. The high-pressure bypass injection low-pressure steam heating mode utilizes the pressure matching device to rationally distribute and regulate steam pressure, reducing energy loss during steam transmission and improving the overall system's thermal efficiency. By adjusting the pressure matching function, excessively high or low steam supply pressure can be effectively prevented, ensuring the safe operation of the heating system and reducing the risk of accidents. This invention can select a suitable steam supply mode according to user needs and actual operating conditions, optimizing the allocation of steam and water resources and improving the system's economy and operating efficiency. In summary, this method, through the combination of two steam supply modes, fully utilizes energy, ensures stable steam supply pressure, reduces energy loss, and improves the system's safety and economy. Attached Figure Description

[0029] Figure 1 This is a system diagram of the present invention;

[0030] Among them, 1. Boiler; 2. High-pressure cylinder; 3. Medium-pressure cylinder; 4. Pressure matching device; 5. Heat user; 11. Main steam pipeline; 12. First electric valve; 13. High-pressure bypass valve; 14. Second electric valve; 15. Desuperheating water electric valve; 16. Desuperheating water regulating valve; 17. First check valve; 18. Third electric valve; 21. Fourth electric valve; 22. Regulating valve; 23. Second check valve; 24. Fifth electric valve; 31. Sixth electric valve; 32. Seventh electric valve. Detailed Implementation

[0031] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0032] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0036] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0037] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0038] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0039] See Figure 1 A wide-load steam supply system with a high bypass coupling pressure matcher includes a boiler 1. The superheater outlet of the boiler 1 is connected to a high-pressure cylinder 2 via a main steam pipeline 11. The reheater outlet of the boiler 1 is connected to an intermediate-pressure cylinder 3. The low-pressure steam supply pipeline of the intermediate-pressure cylinder 3 is connected to a pressure matcher 4 and a heat user 5. The high-pressure steam supply bypass of the main steam pipeline of the boiler 1 is connected to the pressure matcher 4. The pressure matcher 4 is connected to the heat user 5 and a desuperheating water system.

[0040] A first electric valve 12, a high-pressure bypass valve 13, and a third electric valve 18 are installed on the high-pressure steam supply bypass of boiler 1. The high-pressure steam supply bypass of boiler 1 forms a loop with boiler 1. A second electric valve 14 is installed on the pipeline connecting the high-pressure steam supply bypass to boiler 1. A fourth electric valve 21, a regulating valve 22, and a second check valve 23 are installed on the low-pressure steam supply pipeline of intermediate-pressure cylinder 3. A fifth electric valve 24 is installed on the pipeline connecting the low-pressure steam supply pipeline of intermediate-pressure cylinder 3 to the pressure matching device 4. A sixth electric valve 31 is installed on the pipeline connecting the low-pressure steam supply pipeline of intermediate-pressure cylinder 3 to the heat user 5. A seventh electric valve 32 is installed on the pipeline connecting the pressure matching device 4 to the heat user 5.

[0041] The desuperheating water system includes a water supply pipeline, and a desuperheating water electric valve 15, a desuperheating water regulating valve 16, and a first check valve 17 are installed on the water supply pipeline.

[0042] A method for operating a wide-load steam supply system with a high bypass coupling pressure matcher, including a conventional steam supply mode and a high bypass ejector low-pressure steam heating mode;

[0043] When the unit is operating at high load and using the conventional steam supply mode, the first electric valve 12, the high-pressure bypass valve 13, the third electric valve 18, the desuperheating water electric valve 15, the desuperheating water regulating valve 16, the first check valve 17, the fifth electric valve 24, the seventh electric valve 32, and the sixth electric valve 31 are in the closed state, and the operating method is as follows:

[0044] S11, the reheated steam from boiler 1 is sent into intermediate pressure cylinder 3 to do work;

[0045] S12, the intermediate pressure cylinder 3 adjusts the steam supply to supply steam to the heat user 5.

[0046] When a thermal power unit is operating at low to medium load, adjusting the opening of the rotating diaphragm will result in three scenarios: 1. The steam supply pressure and flow rate cannot meet user needs; 2. Opening the rotating diaphragm to its minimum opening will barely meet user needs, but due to the small opening, throttling losses are too large, resulting in low efficiency of the intermediate-pressure cylinder, poor steam supply economy, and a limited adjustment range; 3. Directly using high-pressure steam for desuperheating and pressure reduction will result in high-grade steam being supplied to low-grade industrial steam. Therefore, when the unit is operating at low load, high-pressure bypass injection of low-pressure steam is required to meet user needs while improving steam supply economy to some extent. At this time, the first electric valve 12, high-pressure bypass valve 13, third electric valve 18, desuperheating water electric valve 15, desuperheating water regulating valve 16, first check valve 17, fifth electric valve 24, and seventh electric valve 32 are in the open state, and the sixth electric valve 31 is in the closed state. The working method of the high-pressure bypass injection of low-pressure steam heating mode is as follows:

[0047] S21, the reheated steam from boiler 1 is sent into intermediate pressure cylinder 3 to do work;

[0048] S22, the steam supply of the intermediate pressure cylinder 3 is sent into the pressure matching device 4;

[0049] S23, the main steam and desuperheating water of boiler 1 are sent into pressure matching device 4;

[0050] S24, the pressure matching device 4 adjusts the pressure of the steam supply of the intermediate pressure cylinder 3, the main steam of the boiler 1, and the desuperheating water to supply steam to the heat user 5.

[0051] This operating mode can adjust the steam flow of the high-pressure bypass pipeline and the low-pressure steam supply pipeline according to the unit load and user flow requirements, so as to minimize the overall steam supply economy.

[0052] Example:

[0053] This system comprises the following main components:

[0054] Boiler 1 is used to generate reheat steam and main steam.

[0055] The intermediate pressure cylinder 3 is used to perform work using reheated steam and to adjust the steam supply.

[0056] Pressure matching device 4 is used to regulate the pressure of steam supply to the intermediate pressure cylinder, main steam of the boiler, and desuperheating water.

[0057] Heat user 5 is used to receive steam.

[0058] Various electric valves and regulating valves are used to control the flow of steam and water.

[0059] Conventional steam supply mode (high load operation):

[0060] When the unit is operating at high load, the system adopts the conventional steam supply mode. At this time, the status of each valve is as follows:

[0061] Closed: First electric valve 12, high-pressure bypass valve 13, third electric valve 18, desuperheating water electric valve 15, desuperheating water regulating valve 16, first check valve 17, fifth electric valve 24 and seventh electric valve 32.

[0062] Open: Sixth electric valve 31.

[0063] The working steps of the conventional steam supply mode are as follows:

[0064] S11: The reheated steam from boiler 1 is sent to intermediate pressure cylinder 3 to perform work.

[0065] S12: The intermediate pressure cylinder 3 adjusts the steam supply to supply steam to the heat user 5.

[0066] High-pressure steam heating mode with side-ejector (medium and low load operation):

[0067] When the unit is operating at low load, the system adopts a high-pressure bypass injection low-pressure steam heating mode. At this time, the status of each valve is as follows:

[0068] Open: First electric valve 12, high pressure bypass valve 13, third electric valve 18, desuperheating water electric valve 15, desuperheating water regulating valve 16, first check valve 17, fifth electric valve 24, seventh electric valve 32.

[0069] Close: Sixth electric valve 31.

[0070] The operating steps of the side-ejector low-pressure steam heating mode are as follows:

[0071] S21: The reheated steam from boiler 1 is sent to intermediate pressure cylinder 3 to perform work.

[0072] S22: Steam from the intermediate pressure cylinder 3 is supplied to the pressure matching device 4.

[0073] S23: The main steam and desuperheating water of boiler 1 are sent into pressure matching device 4.

[0074] S24: Pressure matching device 4 adjusts the steam supply pressure of intermediate pressure cylinder 3, the main steam pressure of boiler 1, and the desuperheating water pressure to supply steam to heat user 5.

[0075] Actual numerical examples:

[0076] Assumption:

[0077] Boiler reheat steam parameters: temperature 540℃, pressure 3.5MPa.

[0078] Boiler main steam parameters: temperature 540℃, pressure 12MPa.

[0079] Steam parameters at the outlet of the intermediate pressure cylinder: temperature 350℃, pressure 2MPa.

[0080] Hot user requirements: pressure 1MPa, flow rate 20t / h.

[0081] High-load operation (conventional steam supply mode):

[0082] Reheat steam flow rate: 100t / h is fed into intermediate pressure cylinder 3.

[0083] The outlet flow rate of the intermediate pressure cylinder is 80t / h for power generation and 20t / h for steam supply to heat users.

[0084] Medium and low load operation (high bypass injection low-pressure steam heating mode):

[0085] Reheat steam flow rate: 50t / h is fed into intermediate pressure cylinder 3.

[0086] Medium-pressure cylinder outlet flow rate: 40t / h for power generation, 10t / h for feeding into pressure matching device 4.

[0087] Main steam flow rate: 10t / h is fed into pressure matching device 4.

[0088] Desuperheating water flow rate: Adjust appropriately to meet the steam supply temperature requirements (e.g., 5t / h).

[0089] In pressure matching unit 4, steam and desuperheating water are mixed and adjusted to supply steam to heat user 5 with parameters of 1MPa and 20t / h.

[0090] This invention is flexible and adaptable to load changes: it can efficiently supply steam under both high and medium-low load conditions.

[0091] This invention optimizes energy utilization by improving the steam supply economy during medium and low load operation through high-pressure bypass injection of low-pressure steam.

[0092] This invention stabilizes steam supply pressure: the pressure matching device ensures stable steam supply pressure to meet user needs.

[0093] This invention reduces throttling losses: during low-load operation, it avoids energy waste caused by throttling.

[0094] This embodiment demonstrates the specific operating methods and advantages of the system under different load conditions, achieving efficient steam supply over a wide load range.

[0095] This invention's high-side-ejector low-pressure steam heating mode utilizes a pressure matcher to rationally distribute and regulate steam pressure, reducing energy loss during steam transmission and improving the overall system's thermal efficiency. Through the pressure matcher's adjustment function, this invention effectively prevents excessively high or low steam supply pressure, ensuring the safe operation of the heating system and reducing the risk of accidents. This invention allows for the selection of a suitable steam supply mode based on user needs and actual operating conditions, resulting in optimized allocation of steam and water resources and improving the system's economy and operational efficiency.

[0096] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0097] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for operating a wide-load steam supply system with a high bypass coupling pressure matcher, characterized in that, The wide-load steam supply system includes a boiler (1), the superheater outlet of the boiler (1) is connected to the high-pressure cylinder (2) through the main steam pipeline (11), the reheater outlet of the boiler (1) is connected to the medium-pressure cylinder (3), the low-pressure steam supply pipeline of the medium-pressure cylinder (3) is connected to the pressure matching device (4) and the heat user (5), the high-pressure steam supply bypass of the main steam pipeline of the boiler (1) is connected to the pressure matching device (4), the pressure matching device (4) is connected to the heat user (5), and the pressure matching device (4) is connected to the desuperheating water system; The operating methods include conventional steam supply mode and high-pressure side-ejector low-pressure steam heating mode; The working method of the conventional steam supply mode is as follows: The reheated steam from boiler (1) is sent into intermediate pressure cylinder (3) to do work; The intermediate pressure cylinder (3) adjusts the steam supply to supply steam to the heat users (5); The operating method of the high-pressure side-ejector low-pressure steam heating mode is as follows: The reheated steam from boiler (1) is sent into intermediate pressure cylinder (3) to do work; Steam from the intermediate pressure cylinder (3) is fed into the pressure matching device (4); The main steam and desuperheating water of the boiler (1) are fed into the pressure matching device (4); The pressure matching device (4) adjusts the steam supply of the intermediate pressure cylinder (3), the pressure of the main steam and desuperheating water of the boiler (1), and supplies steam to the heat users (5); A fifth electric valve (24) is installed on the connection line between the low-pressure steam supply line of the intermediate-pressure cylinder (3) and the pressure matching device (4), and a sixth electric valve (31) is installed on the connection line between the low-pressure steam supply line of the intermediate-pressure cylinder (3) and the heat user (5). In the normal steam supply mode, the fifth electric valve (24) is in the closed state and the sixth electric valve (31) is in the open state; The boiler (1) is equipped with a first electric valve (12), a high-pressure bypass valve (13) and a third electric valve (18) on the high-pressure steam supply bypass. The desuperheating water system includes a pipeline connected to the water supply. The pipeline connected to the water supply is equipped with a desuperheating water electric valve (15), a desuperheating water regulating valve (16) and a first check valve (17). The pressure matching device (4) is connected to the heat user (5) by a seventh electric valve (32). In the high-pressure bypass low-pressure steam heating mode, the first electric valve (12), the high-pressure bypass valve (13), the third electric valve (18), the desuperheating water electric valve (15), the desuperheating water regulating valve (16), the first check valve (17), the fifth electric valve (24), and the seventh electric valve (32) are in the open state, and the sixth electric valve (31) is in the closed state.

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