Optimized water drainage structure of internal dehumidification device

Abstract

This invention discloses an optimized drainage structure for an internal dehumidifier, comprising an inner ring drainage structure and an outer ring drainage structure. The inner ring of the upper half of the internal dehumidifier and the outer ring of the lower half of the internal dehumidifier, as well as the inner ring, are provided with water storage tanks for water droplets to fall onto multiple rows of corrugated plates. An additional drainage groove is added to the inner ring of the lower half of the internal dehumidifier. The inner ring of the upper half of the internal dehumidifier has a slanted drainage hole on its midpoint, and the bottom of the outer ring of the lower half of the internal dehumidifier has drainage holes. This invention, by adding an inner ring drainage groove to the traditional outer ring drainage structure of the internal dehumidifier, and simultaneously enlarging the drainage groove opened between the outer drainage holes and the cylinder, effectively accelerates the drainage speed, improves the problem of water accumulation due to poor drainage overflowing the baffle plate and being carried into the low-pressure section, increasing the humidity in the low-pressure section, and reduces the erosion of the terminal blades by wet steam.

Description

Technical Field

[0001] This invention relates to the field of steam turbines, and more specifically to an internal dehumidification structure for a marine nuclear-powered steam turbine. Background Technology

[0002] In nuclear-powered steam turbines and other low-parameter steam turbines, because the initial steam parameters are already close to or have reached saturation, the steam expands to a certain extent in the low-pressure section of the turbine and spontaneously condenses to form condensation nuclei, resulting in wet steam. The generation of a large amount of wet steam in the low-pressure stage mainly leads to two problems: first, it reduces the aerodynamic efficiency and work capacity of the turbine stage operating in the wet steam region; second, water droplets in the wet steam can cause water erosion damage to the turbine blades in the last few stages. Long-term design and operational experience has proven that the maximum humidity of the steam in the last stage of the turbine should not exceed 10% to 12%, otherwise it will seriously affect the turbine's service life and safe operation.

[0003] To avoid the aforementioned problems, marine steam turbine generator sets, considering the limited cabin space, adopt an internal dehumidification device structure, which is located between the high-pressure cylinder and the low-pressure cylinder of the unit (see reference). Figure 1 Its functions include two aspects: first, separating water droplets from the supersaturated steam at the high-pressure cylinder outlet to reduce humidity; and second, reheating the circulating steam after steam-water separation to improve circulation efficiency. Many factors affect the dehumidification efficiency of the internal dehumidifier, including steam velocity, baffle height, and drainage efficiency. If the water droplets separated by the internal dehumidifier are not discharged through the drainage channel in time, they will be carried by the steam into the low-pressure section flow, leading to increased humidity in the low-pressure section, indirectly reducing the dehumidification efficiency of the internal dehumidifier, and increasing the risk of water erosion on the last-stage blades.

[0004] Current internal dehumidifiers all use a single outer ring hydrophobic structure (see reference). Figure 2 When the ship is tilting and rolling, the internal dehumidifier tilts to one side, which will cause the condensate on one side to flow towards the middle of the arc without the condensate holes arranged on the outer ring. Since there are no condensate holes in the inner ring of the arc section, more and more water droplets accumulate and eventually pass over the baffle plate and are carried by the high-velocity steam to the low-pressure passage section, resulting in an increase in humidity in the low-pressure section of the steam turbine.

[0005] Among the existing related patent technologies, such as the corrugated internal dehumidification structure for steam turbines disclosed in patent document (CN106246248A), the design of this patent does not adequately consider the dynamic working conditions (tilting, rolling, vibration) unique to ships. Under the conditions of ship roll, pitch, or rolling, "bottom" is a dynamic and relative concept. When the device tilts to one side, the water in the lower half-ring outer ring water tank (4) will flow and accumulate along the circumferential direction (middle of the middle arc) due to gravity. Since this patent only sets drainage holes (7) at the "bottom", after tilting, the original bottom drainage holes may move to a higher position, while the middle arc section where water actually accumulates is not set with drainage holes. As the water accumulation increases and the water level rises, under the shearing force of the high-velocity steam inside the steam turbine, the accumulated water droplets are very likely to cross the water-blocking edge of the corrugated plate (3) and be re-entrained by the steam (i.e., "secondary entrainment"), directly entering the low-pressure section (13), which will aggravate the erosion of the blades in the low-pressure section.

[0006] Therefore, optimizing the hydrophobic structure of the internal dehumidification device is particularly important for improving the dehumidification efficiency of marine steam turbine generator sets under tilting and swaying conditions. Summary of the Invention

[0007] The purpose of this invention is to provide an optimized drainage structure for an internal dehumidifier. By optimizing the drainage structure of the internal dehumidifier through adaptive design, the problem of untimely drainage of the internal dehumidifier under the special tilting and swaying conditions of marine steam turbine generator sets is solved, providing a better drainage solution for the internal dehumidifier of marine steam turbine generator sets.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] An optimized internal dehumidification device with a hydrophobic structure includes an internal dehumidification device composed of an inner ring hydrophobic structure and an outer ring hydrophobic structure. The inner ring of the upper half ring and the outer ring and inner ring of the lower half ring of the internal dehumidification device are provided with water storage tanks for water droplets to fall into the multi-row corrugated plates, and a hydrophobic tank is added to the inner ring of the lower half ring.

[0010] Furthermore, the inner half of the upper ring of the internal dehumidifier is provided with a sloping groove drainage hole on the split surface of the inner ring, and the bottom of the outer ring of the lower half of the internal dehumidifier is provided with a drainage hole.

[0011] Furthermore, the water drained from the corrugated plate in the central area of ​​the upper half ring of the internal dehumidification device flows into the drainage channel of the lower half ring through the drainage hole of the inclined groove on the middle surface of the upper half ring under the action of gravity, and then flows out of the turbine through the drainage hole at the bottom. The water droplets in the corrugated plate in the central area of ​​the lower half ring that are not drained in time by the drainage hole of the inner ring, as well as the water drained from the corrugated plates in the two sides areas, flow into the drainage channel of the lower half ring through the drainage hole of the inclined groove on the middle surface of the upper half ring under the action of gravity, and then flow out of the turbine after merging with the water drained from the inner ring through the drainage hole at the bottom.

[0012] Furthermore, when the hull is tilting and rolling, the simultaneous drainage of the inner and outer rings of the internal dehumidification device ensures that even if the collected water droplets gather to one side, they can still be dispersed in time.

[0013] Furthermore, the hydrophobic structure also expands the external drainage port of the internal dehumidification device, and the cylinder is equipped with a drainage groove to accelerate the drainage speed and avoid water accumulation or poor drainage.

[0014] Compared with the prior art, the present invention has the following advantages: This invention improves upon the traditional outer ring drainage structure of an internal dehumidifier by adding an inner ring drainage groove and enlarging the drainage groove created by the external drainage holes of the internal dehumidifier to align with the cylinder. This effectively accelerates the drainage speed and improves the problem of water accumulation due to poor drainage, which overflows the baffle plate and is carried into the low-pressure section, increasing the humidity in the low-pressure section. It also reduces the erosion of the terminal blades by wet steam. (Reference) Figure 3 ). Attached Figure Description

[0015] Figure 1 This is an installation diagram of the present invention; Figure 2 This is a schematic diagram of the drainage of a traditional internal dehumidification device that uses a single outer ring for drainage; Figure 3 This is a schematic diagram of the drainage of the internal dehumidification device with an optimized inner and outer ring hydrophobic structure. Figure 4 The effect curve of different baffle heights on dehumidification efficiency; Figure 5 This is a schematic diagram of an optimized internal dehumidification device according to the present invention; Figure 6 This is a schematic diagram of the specific hydrophobic path of an optimized internal dehumidification device according to the present invention; Figure 7 This is a schematic diagram of the external drainage port structure of an optimized internal dehumidification device according to the present invention; Figure 8 This is a schematic diagram of the structure with drainage channels for the turbine cylinder. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] This invention further illustrates the dehumidification effect of an optimized hydrophobic structure in an internal dehumidification device. See the schematic diagram for details. Figures 4-8 As shown.

[0018] Research indicates that the height of the baffle plate in an internal dehumidifier significantly impacts dehumidification efficiency. Increasing the baffle plate height from 15mm to 120mm maintains a dehumidification efficiency of over 98% even with a face wind speed of 8-10 m / s. Furthermore, increasing the baffle plate height better prevents condensate from overflowing and being carried into the low-pressure flow path by the airflow (see schematic diagram for details). Figure 4 ).

[0019] Increasing the height of the baffle plate to improve dehumidification efficiency essentially prevents water droplets separated by the corrugated plate from accumulating and eventually overflowing the baffle plate into the low-pressure flow path. Therefore, fundamentally solving the problem of poor drainage can also effectively improve the dehumidification efficiency of internal dehumidification devices.

[0020] like Figure 3 As shown in Figures 5, 6, 7, and 8, an optimized internal dehumidification device drainage structure is provided. By adding an inner drainage groove to the traditional outer drainage structure, and by expanding the external drainage holes of the internal dehumidification device to cooperate with the drainage groove opened in the cylinder, the drainage speed can be effectively accelerated, avoiding the problem of water flow being carried to the low-pressure section due to poor drainage and the water flow passing over the baffle plate.

[0021] The internal dehumidification device consists of an upper ring and a lower ring. The inner ring of the upper ring and the outer ring of the lower ring, as well as the inner ring of the lower ring, are equipped with water storage tanks for water droplets to fall onto the multi-row corrugated plates. Water from the corrugated plates in the central area of ​​the upper ring flows by gravity from the inner ring through the drainage holes on the split surface into the drainage channel of the inner ring of the lower ring, and then exits the turbine through the drainage holes at the bottom. Water droplets from the corrugated plates in the central area of ​​the lower ring that are not promptly drained by the drainage holes in the inner ring, as well as water from the corrugated plates in the side areas, flow by gravity from the inner ring of the upper ring through the drainage holes on the split surface into the drainage channel of the outer ring of the lower ring, and then merge with the inner ring water at the drainage holes at the bottom before exiting the turbine (see schematic diagram for details). Figure 6 Compared to a single outer ring drainage, the advantages of an optimized drainage structure become more significant under shipboard tilting and rolling conditions. When the internal dehumidification device tilts along with the turbine generator set and the hull, simultaneous drainage of the inner and outer rings ensures that even if the collected water droplets gather to one side, they can still be dispersed in a timely manner.

[0022] Meanwhile, to ensure timely drainage, the optimized drainage structure enlarges the external drainage outlet of the internal dehumidifier (see schematic diagram for details). Figure 7 At the same time, a drain groove is opened in the cylinder (see schematic diagram for details). Figure 8 This speeds up the drainage process and prevents water accumulation or poor drainage.

Claims

1. An optimized hydrophobic structure for an internal dehumidification device, characterized in that: The device includes an internal dehumidification unit consisting of an inner ring hydrophobic structure and an outer ring hydrophobic structure. The inner ring of the upper half ring and the outer ring and inner ring of the lower half ring of the internal dehumidification unit are provided with water storage tanks for water droplets to fall into the multi-row corrugated plates, and an additional inner ring hydrophobic tank is provided in the lower half ring.

2. The optimized hydrophobic structure of the internal dehumidification device according to claim 1, characterized in that: The inner half of the upper ring of the internal dehumidifier has a sloping groove drainage hole on the middle surface of the inner ring, and the bottom of the outer ring of the lower half of the internal dehumidifier has a drainage hole.

3. The optimized hydrophobic structure of the internal dehumidification device according to claim 2, characterized in that: The water droplets from the corrugated plate in the central area of ​​the upper half ring of the internal dehumidification device flow into the lower half ring's inner ring drainage channel through the drainage holes in the inclined groove of the split surface under gravity. Then, they flow out of the turbine through the drainage holes at the bottom. The water droplets from the corrugated plate in the central area of ​​the lower half ring that are not promptly drained by the drainage holes in the inner ring, as well as the water droplets from the corrugated plates in the two sides, flow into the lower half ring's outer ring drainage channel through the drainage holes in the inclined groove of the split surface under gravity. Then, they merge with the inner ring drainage at the drainage holes at the bottom and flow out of the turbine.

4. The optimized hydrophobic structure of the internal dehumidification device according to claim 1, characterized in that: When the ship is tilting and rolling, the simultaneous drainage of the inner and outer rings of the internal dehumidification device can ensure that even if the collected water droplets gather to one side, they can still be dispersed in time.

5. The optimized hydrophobic structure of the internal dehumidification device according to claim 1, characterized in that: The hydrophobic structure also expands the external drainage port of the internal dehumidification device, and the cylinder is equipped with a drainage groove to accelerate the drainage speed and avoid water accumulation or poor drainage.

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