Development direction, parameter selection and use

2022-08-09
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Development direction and parameter selection and use of nuclear power valves

1. Development direction of nuclear power units

according to data analysis, in the construction of nuclear power plants, the development direction of unit capacity is mainly 1.3 million, 1.4 million and 1.5 million KW abroad. China is mainly developing towards 800000, 900000 and 1million. Nuclear power equipment will develop towards large-scale, high parameter and high performance

2. development direction of nuclear power valves

with the development of nuclear industry, the requirements for large-scale, high parameter, high performance, reliability and safety of nuclear power plant equipment are becoming higher and higher. This requires that nuclear power valves can also adapt to this development trend

The specific types and parameters of valves for nuclear power are as follows:

⑴ gate valve without stuffing box:

improve scientific management level a hydraulic drive gate valve. The valve uses its own pressure water to push the piston to open or close. The nominal diameter of the valve: DN350, 400mm; Working pressure: pn17.5mpa; Working temperature: 315 ℃

b fully enclosed electric gate valve. The valve shall adopt a special screen closed motor to make the ram open and close through the inner planetary reducer working in water. Nominal diameter of the valve: dn100~800mm; Working pressure: pn2.5~45.0mpa; Working temperature: 200~500 ℃

(Note: the above two kinds of non stuffing box gate valves have the advantages of no stuffing seal, avoiding external leakage points, and reducing energy consumption. Disadvantages: complex structure and high cost.)

⑵ stop valve:

used for stop valve on auxiliary pipeline

the valve usually has three structures, namely, packing stop valve, bellows stop valve and metal diaphragm stop valve. The medium of the valve is water and steam with medium parameters (medium temperature and medium pressure); Nominal diameter: dn10~150mm

⑶ butterfly valve:

butterfly valve used in cooling system and system conveying air medium in containment. The valve usually has three structures, namely, coaxial direct connected rubber lined butterfly valve, eccentric metal seal butterfly valve and double acting metal seal butterfly valve (the sealing surface is disengaged before the butterfly plate rotates). Nominal diameter of the valve: DN ≤ 2500mm; Working pressure: PN < 4.0Mpa; Working temperature: 100~150 ℃. In addition, the nominal diameter of fast closing butterfly valve used in air duct system: dn400~1200mm is also listed as the development direction

⑷ pilot safety valve with detector:

used for pilot safety valve with detector in nuclear island system. Using the pilot type safety valve with detector, the principle of two contacts for position control release and medium filling can be changed according to the sensitive relationship between pressure and spring force balance, so as to avoid jamming in structure. The valve adopts a positive acting disc structure with spring preload and bellows seal, which can ensure reliable sealing. Nominal diameter of the valve: DN600mm; Working pressure: pn1.265mpa

(5) check valve type isolation valve:

check valve type isolation valve for steam system, its structure and shape are similar to lift check valve. Nominal diameter of the valve: dn64~800mm (21/2in~30in); Working pressure: pn1.0~42.0mpa (class600~2500); Working temperature: -29~1050 ℃

(6) main steam isolation valve

main steam isolation valve for nuclear island and conventional island Shandong new chemical materials industry through cluster development, Main Feedwater valve, its nominal diameter: DN800mm; Nominal pressure: 40.0mpa; Temperature 700 ℃

in addition, the measured values for 905 nm and 1540 nm laser rangefinders are related to the position of the fracture. Safety valves that meet the seismic requirements, soft and hard sealed high vacuum solenoid valves for nuclear fuel extraction, and top mounted nuclear power ball valves are also nuclear power valves that need to be developed urgently

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