Air extractor structure with bypass steam distribution
By adding a bypass steam distribution mechanism and an electric angle valve to the steam inlet structure of the ejector, the problem of flow self-adaptation of the ejector under low parameter conditions was solved, ensuring that the ejector has sufficient suction capacity under low parameter conditions and realizing the normal operation of the marine secondary loop system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- THE 704TH RES INST OF CHINA STATE SHIPBUILDING CORP
- Filing Date
- 2025-05-23
- Publication Date
- 2026-05-12
AI Technical Summary
Conventional ejectors have difficulty operating normally under low-parameter conditions when steam parameters change, which makes it impossible to meet the suction capacity requirements of marine secondary circuit systems for condensers and shaft seals during startup and lower operating conditions.
Design a steam ejector structure with bypass steam distribution. By adding a bypass steam distribution mechanism to the steam inlet structure of the ejector, the steam flow rate is adjusted by an electric angle valve to ensure that the steam flow rate increases under low parameter conditions and meets the suction requirements.
实现了抽气器在低参数工况下具有足够的抽吸能力，保证了船用二回路系统在启动工况和较低工况下的正常运转，满足冷凝器和汽轮机汽封抽气系统的需求。
Smart Images
Figure CN224229750U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of marine secondary circuits and steam turbines, specifically an ejector structure that enables wide-condition operation through a bypass steam distribution mechanism, and is particularly suitable for marine systems with frequent fluctuations in steam parameters. Background Technology
[0002] Conventional ejectors are designed with high parameters of the rated operating steam. Once selected, they mainly operate under one type of high-parameter steam. When the operating steam parameters change, the ejector will deviate from the design conditions or even fail to work properly.
[0003] Existing technologies, such as CN119196648A, disclose a steam absorption and revaporation device. Although the circulation system is optimized through a bypass pipe, its core is steam compression and revaporation, and it does not solve the problem of flow rate adaptation of the ejector under low-parameter operating conditions. Therefore, there is an urgent need for an ejector that can adapt to a wide range of steam parameters, has a simple structure, and is highly reliable. Summary of the Invention
[0004] This invention proposes a novel ejector structure with bypass steam distribution. By adding a bypass steam distribution mechanism to the ejector's steam inlet structure, the ejector can still operate reliably when the working steam parameters decrease from high parameters, and can even achieve a considerable or good vacuum degree under low parameter conditions, thus meeting the requirements of marine secondary loop systems for condenser and shaft seal suction capacity under startup and lower operating conditions.
[0005] To achieve the above objectives, the technical solution of this utility model is: a steam ejector structure with bypass steam distribution, including a working steam inlet pipe, a throttling orifice plate, a steam inlet distributor, an angle valve, a bypass steam distribution pipe, and an ejector. A bypass steam distribution pipe is connected in parallel at both ends of the throttling orifice plate of the working steam inlet pipe, and an angle valve for controlling the bypass steam flow is provided in the bypass steam distribution pipe.
[0006] Furthermore, the working steam inlet pipe is connected to the ejector through the steam distribution body, and the bypass steam distribution pipe is directly connected to the steam header of the steam distribution body.
[0007] Furthermore, the angle valve is an electric angle valve, and its opening degree is adjusted in real time by the controller according to the steam parameters.
[0008] Furthermore, the orifice diameter of the throttling orifice plate is 30%-50% of the inner diameter of the working steam inlet pipe, and its position is close to the inlet end of the steam distribution body.
[0009] Furthermore, the ejector consists of a first-stage ejector and a second-stage ejector, which share the same steam inlet distribution body.
[0010] Furthermore, the diameter of the bypass steam distribution pipe is 1.2-1.5 times that of the working steam inlet pipe.
[0011] Furthermore, the steam inlet distributor and the ejector are connected by a flange seal, and the flange face is equipped with a graphite spiral wound gasket.
[0012] The beneficial effects of this utility model are:
[0013] This invention employs a bypass steam distribution structure. Under high-parameter operating conditions, the working steam flow rate in the original inlet pipeline remains unchanged, and the ejector operates normally. Under low-parameter operating conditions, the bypass pipe angle valve is opened, allowing the working steam to bypass the orifice plate and directly enter the ejector. The main pipe flow channel is much larger than the original pipe with the orifice plate, resulting in a significant increase in steam flow rate. This allows the ejector to receive a larger amount of working steam under low-parameter operating conditions, thus ensuring sufficient suction capacity and achieving the required vacuum level even at low parameters. This effectively solves the problem of evacuating air from the condenser and maintaining a slight negative pressure in the turbine steam seal ejection system of a marine secondary loop system during startup and at lower operating conditions, thereby ensuring the normal operation of all turbine equipment in the secondary loop system. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the ejector structure with bypass steam distribution;
[0015] Figure 2 This is a three-dimensional schematic diagram of an ejector with bypass steam distribution;
[0016] Figure 3 This is a schematic diagram illustrating the structural principle of an ejector system with bypass steam distribution.
[0017] In the diagram: 1. Working steam inlet pipe, 2. Orifice plate, 3. Steam inlet distributor, 4. Angle valve, 5. Bypass steam distribution pipe, 6. Ejector. Detailed Implementation
[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0019] like Figures 1 to 3 As shown, the ejector structure with bypass steam distribution of this utility model mainly includes 6 parts: working steam inlet pipe 1, orifice plate 2, steam distribution body 3, angle valve 4, bypass steam distribution pipe 5, and ejector 6. In the working steam inlet pipe 1 of the ejector, a bypass steam distribution pipe 5 with angle valve 4 is connected in parallel at both ends of the orifice plate 2.
[0020] The working steam inlet pipe 1 is connected to the ejector 6 through the steam distribution body 3, and the bypass steam distribution pipe 5 is directly connected to the steam header of the steam distribution body 3.
[0021] Preferably, the angle valve 4 is an electric angle valve, and its opening degree is adjusted in real time by the controller according to the steam parameters.
[0022] Preferably, the orifice diameter of the throttling orifice plate 2 is 30%-50% of the inner diameter of the working steam inlet pipe 1, and its position is close to the inlet end of the steam distribution body 3.
[0023] Preferably, the ejector 6 consists of a first-stage ejector and a second-stage ejector, and the first-stage ejector and the second-stage ejector share the same steam inlet distributor 3.
[0024] Preferably, the diameter of the bypass steam distribution pipe 5 is 1.2-1.5 times that of the working steam inlet pipe 1.
[0025] Preferably, the steam inlet distributor 3 and the ejector 6 are connected by a flange seal, and the flange face is provided with a graphite spiral wound gasket.
[0026] When operating at high parameters under rated conditions, the angle valve is closed, and there is no steam in the bypass steam distribution line. When operating at low parameters, the angle valve is opened, the bypass steam distribution line is activated, and the working steam flow rate entering the two ejectors 6 is significantly increased.
[0027] By using a bypass steam distribution structure, under high-parameter operating conditions, the working steam flow rate in the original inlet pipeline remains unchanged, and the ejector operates normally. Under low-parameter operating conditions, the bypass pipe angle valve is opened, allowing the working steam to bypass the orifice plate and directly enter the ejector. The main pipe flow channel is much larger than the original pipe with the orifice plate, resulting in a significant increase in steam flow rate. This allows the ejector to receive a larger amount of working steam under low-parameter operating conditions, thus ensuring sufficient suction capacity and achieving the required vacuum level even at low parameters. This effectively solves the problem of the marine secondary loop system's ability to extract air from the condenser and maintain a slight negative pressure in the turbine steam seal ejection system during startup and at lower operating conditions, thereby ensuring the normal operation of all turbine equipment in the secondary loop system.
Claims
1. A vacuum ejector structure with bypass steam distribution, characterized in that: It includes a working steam inlet pipe, a throttling orifice plate, a steam distribution body, an angle valve, a bypass steam distribution pipe, and an ejector. The two ends of the throttling orifice plate of the working steam inlet pipe are connected in parallel to a bypass steam distribution pipe, and the bypass steam distribution pipe is equipped with an angle valve for controlling the bypass steam flow.
2. The ejector structure with bypass steam distribution according to claim 1, characterized in that: The working steam inlet pipe is connected to the ejector through the steam distribution body, and the bypass steam distribution pipe is directly connected to the steam header of the steam distribution body.
3. The ejector structure with bypass steam distribution according to claim 1, characterized in that: The angle valve is an electric angle valve, and its opening degree is adjusted in real time by the controller according to the steam parameters.
4. The ejector structure with bypass steam distribution according to claim 1, characterized in that: The orifice diameter of the throttling orifice plate is 30%-50% of the inner diameter of the working steam inlet pipe, and its position is close to the inlet end of the steam distribution body.
5. The ejector structure with bypass steam distribution according to claim 1, characterized in that: The ejector consists of a first-stage ejector and a second-stage ejector, which share the same steam inlet distribution body.
6. The ejector structure with bypass steam distribution according to claim 1, characterized in that: The diameter of the bypass steam distribution pipe is 1.2-1.5 times that of the working steam inlet pipe.
7. The ejector structure with bypass steam distribution according to claim 1, characterized in that: The steam inlet distributor and the ejector are connected by a flange seal, and the flange face is equipped with a graphite spiral wound gasket.