Small machine exhaust dual-path recovery and back pressure regulation system

Abstract

This invention discloses a dual-path recovery and back pressure control system for exhaust steam from a small turbine, relating to the field of energy-saving technology for thermal systems. The system includes a feedwater pump turbine, an atmospheric deaerator, a high-pressure deaerator, a relay pump, and a water jet ejector. The exhaust steam from the small turbine is divided into two paths: under normal operating conditions, it is discharged into the atmospheric deaerator; under extreme operating conditions, high-pressure water from the relay pump outlet drives the water jet ejector to guide the exhaust steam to the high-pressure deaerator for recovery. This invention can automatically control the back pressure of the small turbine, avoiding heat loss, resource waste, and noise pollution caused by exhaust steam reaching the air. It has advantages such as energy saving and consumption reduction, safety and reliability, low modification cost, simple maintenance, and high degree of automation, and is suitable for thermal power plant thermal systems equipped with atmospheric and high-pressure deaerators.

Description

Technical Field

[0001] This invention relates to the field of energy-saving technology for thermal systems, and in particular to a dual-path recovery and back pressure regulation system for exhaust steam from a small turbine. Background Technology

[0002] In conventional thermal power plant designs, the exhaust steam from the feedwater pump turbine is typically discharged into an atmospheric deaerator. This method utilizes the latent heat of vaporization of the exhaust steam to heat the deoxygenated water, achieving basic small-scale turbine exhaust heat recovery and deoxygenation functions. It features a simple system and reliable operation.

[0003] However, in actual operation, especially under extreme high temperatures in summer, the heat entering the atmospheric deaerator increases significantly when the makeup water temperature rises or when the system condensate flow is large. Excessive heat leads to increased internal pressure. This directly causes an increase in the turbine exhaust back pressure, resulting in poor turbine exhaust and seriously threatening the safe operation of the feedwater pump.

[0004] Currently, the conventional solution to the above problem is to install an air vent pipe on the turbine's exhaust pipe. When the turbine's exhaust back pressure is too high, the air vent valve is opened to directly release the excess steam into the atmosphere. While this approach can temporarily alleviate the back pressure problem, it results in significant heat loss, resource waste, and noise pollution. Existing technology lacks a mechanism that can regulate the turbine's back pressure and achieve automatic exhaust steam recirculation without adding new high-energy-consuming power equipment.

[0005] Therefore, it is necessary to propose a dual-path recovery and back pressure control system for small turbine exhaust steam based on water jet ejection to solve the above problems. Summary of the Invention

[0006] The main objective of this invention is to provide a dual-path recovery and back pressure regulation system for small turbine exhaust steam, aiming to solve existing technical problems.

[0007] To achieve the above objectives, the present invention provides a dual-path recovery and back pressure regulation system for small turbine exhaust steam, comprising: The steam turbine for the feedwater pump has its exhaust port connected to the exhaust manifold. An atmospheric deaerator, wherein the first branch pipe of the exhaust main is connected to the heating steam inlet of the atmospheric deaerator; High-pressure deaerator; The relay pump has its inlet connected to the outlet of the atmospheric deaerator and its outlet connected to the inlet of the high-pressure deaerator and the drive water pipeline, respectively. The water jet ejector has its driving fluid inlet connected to the relay pump outlet via the driving water pipeline, its ejector fluid suction inlet connected to the exhaust main pipe via the second branch pipe of the exhaust main pipe, and its outlet connected to the steam inlet of the high-pressure deaerator via the mixing fluid pipeline. Furthermore, it also includes a pressure detection device, which is installed on the atmospheric deaerator to detect the internal pressure of the atmospheric deaerator and feed back a pressure signal.

[0008] Furthermore, it also includes a drive water regulating valve, which is located on the drive water pipeline and is used to adjust the opening degree according to the signal of the pressure detection device, so as to regulate the working state of the water jet ejector and the back pressure of the small turbine. Furthermore, the second branch pipeline is equipped with an electric isolation valve and a check valve. Furthermore, the drive water pipeline is equipped with an electric isolation valve and a drive water regulating valve. Furthermore, the mixed fluid pipeline is equipped with an electric isolation valve and a check valve.

[0009] The beneficial effects of this invention are reflected in: This invention utilizes the outlet water of a relay pump to drive a steam jet ejector under extreme operating conditions, recovering steam that would otherwise need to be discharged into the air to a high-pressure deaerator, achieving "zero-emission" recovery of waste heat and significantly reducing coal consumption for power generation.

[0010] This invention effectively solves the problem of excessive back pressure in the small turbine caused by excess heat in the atmospheric deaerator through dual-path switching, thus ensuring the safe operation of the feedwater pump turbine.

[0011] This invention utilizes the existing relay pump high-pressure water within the system as the driving source, resulting in low system modification costs and high integration.

[0012] The newly added water jet steam extractor has no moving parts, resulting in a low failure rate and simple maintenance.

[0013] This invention, in conjunction with a pressure detection and control device, can achieve automatic regulation of operating conditions and improve the level of automation in power plants. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the dual-path recovery and back pressure regulation system for small turbine exhaust steam of the present invention.

[0015] Explanation of reference numerals in the attached figures: 1. Feedwater pump turbine; 2. Relay pump; 3. Atmospheric deaerator; 4. High-pressure deaerator; 5. Water jet ejector; 9. Pressure detection device; 11. Check valve; 12. Electric isolation valve; 13. Electric isolation valve; 14. Driven water regulating valve; 15. Electric isolation valve; 16. Check valve; 200. Main exhaust pipe; 201. First branch pipe; 202. Second branch pipe; 203. Drive water pipe; 204. Mixing fluid pipe; 300. Small turbine exhaust pipe. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1 This invention provides a dual-path recovery and back pressure regulation system for small turbine exhaust steam, including: a feedwater pump turbine 1, a relay pump 2, an atmospheric deaerator 3, a high-pressure deaerator 4, a water jet ejector 5, and supporting pipelines, valves and detection and control devices.

[0018] The exhaust port of the feedwater pump turbine 1 is connected to the exhaust manifold 200, which is divided into two parallel branches: the first branch pipe 201 is connected to the heating steam inlet of the atmospheric deaerator 3, which is the main exhaust path under normal operating conditions; the second branch pipe 202 is connected to the ejector fluid inlet of the water ejector 5, which is the backup exhaust path under extreme operating conditions.

[0019] The inlet of relay pump 2 is connected to the outlet of atmospheric deaerator 3. The outlet of relay pump 2 is divided into two paths: one path is directly connected to the inlet of high-pressure deaerator 4 to complete the conventional water supply; the other path is connected to the drive fluid inlet of water jet ejector 5 through drive water pipeline 203 to provide power water for water jet ejector 5.

[0020] The outlet of the water jet ejector 5 is connected to the steam inlet of the high-pressure deaerator 4 via the mixing fluid pipeline 204. The exhaust steam from the ejector is mixed with the driving water and then sent to the high-pressure deaerator 4 for recycling.

[0021] An electric isolation valve 12 and a check valve 11 are installed sequentially on the second branch pipeline 202; An electric isolation valve 13 and a drive water regulating valve 14 are sequentially installed on the drive water pipeline 203; An electric isolation valve 15 and a check valve 16 are sequentially installed on the mixed fluid pipeline 204.

[0022] A pressure detection device 9 is installed on the atmospheric deaerator 3. The signal output terminal of the pressure detection device 9 is connected to the drive water regulating valve 14 to form a closed-loop automatic control. Specifically, the pressure detection device 9 is a pressure gauge.

[0023] Normal operating mode of this system: When the unit is under normal load, the ambient temperature is suitable, and the pressure of atmospheric deaerator 3 is within the set threshold: The electric isolation valve 12 of the second branch pipeline 202, the electric isolation valve 13 of the drive water pipeline 203, and the electric isolation valve 15 of the mixed fluid pipeline 204 are all closed; the water jet ejector 5 is not in operation, and the system is in an isolated state; all the exhaust steam from the feedwater pump turbine 1 enters the atmospheric deaerator 3 through the exhaust main pipe 200 and the first branch pipeline 201, and uses the heat of the exhaust steam to heat the deoxygenated water, thus completing conventional heat recovery and thermal deoxygenation.

[0024] Extreme operating conditions of this system: When high summer temperatures, high makeup water temperatures, and excessive system condensate flow lead to increased pressure in atmospheric deaerator 3 and the exhaust back pressure of the small turbine approaching the safety limit: The pressure detection device 9 monitors the pressure over-limit signal in real time, and the system automatically triggers the commissioning logic; the electric isolation valves 12, 13, and 15 open sequentially; the high-pressure water from the outlet of the relay pump 2 enters the jet ejector 5 through the drive water pipeline 203, forming a jet negative pressure as the driving fluid; the negative pressure draws part of the exhaust steam from the feedwater pump turbine 1 into the jet ejector 5 through the second branch pipeline 202, and after the steam mixes and is pressurized with the high-pressure water, it is sent to the high-pressure deaerator 4 through the mixed fluid pipeline 204; the pressure detection device 9 provides real-time feedback of the pressure signal and automatically adjusts the opening of the drive water regulating valve 14 to control the ejection volume of the jet ejector 5 and stabilize the pressure of the atmospheric deaerator 3 and the back pressure of the small turbine exhaust steam; the check valves 11 and 16 prevent the backflow of steam or steam-water mixture in the high-pressure deaerator 4 to ensure system safety.

[0025] It should be noted that if the embodiments of the present invention involve directional indicators such as (up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0026] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. Furthermore, "multiple" refers to two or more. Moreover, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-path recovery and back pressure regulation system for small turbine exhaust steam, characterized in that... ,include: The steam turbine of the feedwater pump (1) has its exhaust port connected to the exhaust manifold (200). Atmospheric deaerator (3), the first branch pipe (201) of the exhaust main pipe (200) is connected to the heating steam inlet of the atmospheric deaerator (3); High-pressure deaerator (4); The relay pump (2) is connected to the outlet of the atmospheric deaerator (3) at its inlet and to the inlet of the high-pressure deaerator (4) and the drive water pipeline (203) at its outlet. The water jet ejector (5) has its driving fluid inlet connected to the outlet of the relay pump (2) via the driving water pipeline (203), and its ejector fluid suction inlet connected to the exhaust manifold (200) via the second branch pipeline (202). The outlet of the water jet ejector (5) is connected to the steam inlet of the high-pressure deaerator (4) via the mixing fluid pipeline (204).

2. The dual-path recovery and back pressure control system for small turbine exhaust steam according to claim 1, characterized in that: It also includes a pressure detection device (9), which is installed on the atmospheric deaerator (3) to detect the internal pressure of the atmospheric deaerator (3) and to feed back the pressure signal.

3. The dual-path recovery and back pressure regulation system for small turbine exhaust steam according to claim 2, characterized in that: It also includes a drive water regulating valve (14), which is located on the drive water pipeline (203) and is used to adjust the opening degree according to the signal of the pressure detection device (9) to regulate the working state of the water jet ejector (5) and the back pressure of the small turbine.

4. The dual-path recovery and back pressure control system for small turbine exhaust steam according to claim 1, characterized in that: The second branch pipeline (202) is equipped with an electric isolation valve (12) and a check valve (11).

5. The dual-path recovery and back pressure control system for small turbine exhaust steam according to claim 1, characterized in that: The drive water pipeline (203) is equipped with an electric isolation valve (13) and a drive water regulating valve (14).

6. The dual-path recovery and back pressure control system for small turbine exhaust steam according to claim 1, characterized in that: The mixed fluid pipeline (204) is equipped with an electric isolation valve (15) and a check valve (16).

Images