CN-224228731-U - Main valve of supercritical steam turbine

Abstract

The main steam valve of the supercritical steam turbine comprises a valve casing, an inner valve cover is arranged in the valve casing (1), an inner hole of the valve casing 1 is further provided with a whole circle of installation threads, the main steam valve also comprises a thread ring (3), the thread ring is connected in the valve casing through threads and axially fixes the inner valve cover and a sealing ring, a temperature measuring hole is formed in the outer circle of the valve casing and used for measuring the temperature of an inner cavity of the valve casing, a valve casing flange cover (2) is arranged on the upper end face of the valve casing and fixed on the end face of the valve casing through bolts, a valve core (9) is arranged at the right end of the inner valve cover and fixed on the inner valve cover (4) through a locating pin (13), a valve rod and a valve core connected with the valve rod are arranged in the inner valve cover, and a bushing-shaped sealing ring is arranged between the valve rod and the valve core connected with the inner valve cover. The contact surfaces of the valve core (9) and the valve seat are coated with PVD tungsten metal or alloy.

Inventors

• JI YAN
• LU BIN
• WU RUCHUN
• HUI YI
• Tao Wenchi

Assignees

• 无锡润和叶片制造有限公司

Dates

Publication Date

20260512

Application Date

20250522

Claims (3)

1. 1. A main steam valve of a supercritical steam turbine is characterized by comprising a valve casing, an inner valve cover (4) is arranged in the valve casing (1), an inner hole of the valve casing (1) is further provided with a whole circle of threads for installation, the valve casing further comprises a thread ring (3), the thread ring is connected in the valve casing through threads and is used for axially fixing the inner valve cover and a sealing ring, a temperature measuring hole is formed in the outer circle of the valve casing and is used for measuring the temperature of an inner cavity of the valve casing, a valve casing flange cover (2) is arranged on the upper end face of the valve casing and is fixed on the end face of the valve casing through bolts, a valve core (9) is arranged at the right end of the inner valve cover and is fixed on the inner valve cover (4) through a locating pin (13), a valve rod (11-1) and a valve core connected with the valve rod are arranged in the inner valve cover, a bushing-shaped sealing ring (5) is arranged between the valve rod and the valve core connected with the inner valve cover, a locating sleeve (8) is further arranged between the valve rod and the valve core connected with the valve cover, and the valve seat, and the valve core is provided with a PVD metal or alloy coating.
2. 2. The main steam valve of the supercritical steam turbine according to claim 1, wherein a valve core is arranged at the left end of the valve rod and is fixed at the right end of the inner valve cover through a locating pin, a valve seat (10) is arranged in the valve shell, and the valve seat is in interference fit with the valve shell.
3. 3. The main valve of the supercritical steam turbine according to claim 1, wherein two sets of inner valve covers, valve cores and valve seats are arranged in the valve housing side by side.

Description

Main valve of supercritical steam turbine Technical Field The utility model relates to a structure of a main steam valve of a supercritical steam turbine. Background The supercritical turbine unit is used as a representative of clean coal-electricity technology in universities, and the market prospect is influenced by multiple factors such as global energy transformation, policy guidance, technical innovation, regional requirements and the like. Supercritical turbines will still occupy an important market place in mid-term groups to 2030, especially in asia emerging economies, the survival of which in the long term depends on whether or not they can be integrated into low carbon energy systems by technological innovation. Supercritical turbine sets become the core technology of modern high-efficiency clean coal-fired power generation by breaking through the limit of traditional thermodynamic cycle. Has irreplaceable advantages in improving energy utilization efficiency and reducing carbon emission. The supercritical turbine set is mainly applied to large-scale coal-fired power plants, and is suitable for power demand scenes (such as industrial areas and urban power supply) with high load rate and continuous operation. The reliability of the traditional valve parts is improved by adopting an integral stainless steel, alloy steel or sealing surface overlaying alloy layer mode, but the sealing surface of the valve is extremely high in requirements, the sealing surface cannot meet the sealing requirements in a conventional mode, the sealing surface is high in hardness and corrosion resistance, abrasion resistance and collision resistance, and part of the sealing surface of the part adopts a stellite alloy overlaying mode, but the stellite alloy is relatively expensive, and defects such as cracks and air holes are extremely easy to occur during welding. The existing sealing surface adopts a special PVD coating process, the PVD coating has high hardness (up to 2000-3500HV, far higher than the base material), high temperature resistance (can keep stability above 800 ℃, is suitable for the high temperature environment of a steam turbine), corrosion resistance and low friction coefficient, the PVD coating technology provides an efficient surface strengthening scheme for the steam turbine valve, the production and maintenance cost is greatly reduced, and the service life of the valve part is remarkably prolonged. Disclosure of Invention In order to solve the problems, the utility model aims to prepare the main steam valve of the supercritical steam turbine, and the sealing surface adopts a PVD coating process to solve the problems of easy abrasion, easy corrosion, easy deformation and the like of the sealing surface. The technical scheme includes that the main steam valve of the supercritical steam turbine comprises a valve shell 1, an inner valve cover 4 is arranged in the valve shell 1, an installation whole circle of threads are further arranged in an inner hole of the valve shell 1, the main steam valve also comprises a thread ring 3, the thread ring 3 is connected in the valve shell 1 through threads and axially fixes the inner valve cover 4 and a bushing-shaped sealing ring 5, two temperature measuring holes are formed in the outer circle of the valve shell 1 and are used for measuring the temperature of an inner cavity of the valve shell 1, a valve shell flange cover 2 is arranged on the upper end face of the valve shell 1, the flange cover 2 is fixed on the end face of the valve shell 1 through bolts, a valve core 9 is arranged at the right end of the inner valve cover 4 and is fixed on the inner valve cover 4 through a locating pin 13, a valve rod 11-1 and a connected valve core 11 are arranged in the inner valve cover 4, 4 bushing-shaped sealing rings 5 are arranged between the valve rod 11-1 and the connected valve core 11 and the inner valve cover 4, the valve rod 11-1 is fixed through a locking nut 7, and a locating sleeve 8 is further arranged between the valve rod 11-1 and the connected valve core 11 and the inner valve cover 4. The contact surfaces of the valve core 9 and the valve seat are coated by tungsten metal or alloy PVD. The left end of the valve rod is provided with a valve core 9, and the valve core 9 is fixed at the right end of the inner valve cover 4 through a locating pin 13. A valve seat 10 is further arranged in the valve housing 1, and the valve seat 10 is in interference fit with the valve housing 1. The sealing surface is a key part of the valve, and the quality of the sealing surface directly influences the service life of the valve. The PVD coating has excellent high-temperature mechanical property, corrosion resistance and wear resistance, so that the sealing surface of the PVD coating has the following excellent properties that the hardness of the PVD coating is improved by 5-10 compared with that of a base material, the service life of the sealing surface of the PVD coating is