Viti Fluid Control: An Overall Solution for Harsh Working conditions in Thermal Power Plants

In the thermal power generation industry, valves are key equipment that ensure the safe, stable and efficient operation of units. From the blazing fire of the boiler to the rapid rotation of the steam turbine, from the ultra-supercritical high temperature and high pressure to the strict pressure difference of the drain system, every link cannot do without the precise control and reliable cut-off of valves.

W&T, relying on its German technological heritage and the complete machine production capacity of its Russian production base, provides an overall solution for the thermal power industry, ranging from "steam-water systems, drainage systems, feed water pump systems to desuperheating and pressure reducing systems".

I. Challenges to Valves in the Harsh Working Conditions of Thermal Power Plants

With the continuous advancement of the "upgrading large and phasing out small" and technological transformation in China's power generation industry, ultra-supercritical units have become the main models, with main steam parameters reaching 605℃/27.6MPa, and some secondary reheat units have even reached 630℃/33MPa. Harsh working conditions impose higher requirements on valves:

When the valve is damaged and experiences leakage, it will accelerate the leakage of the valve under harsh working conditions, causing the high-quality medium that should be used for the work of the steam turbine to leak and be wasted, directly increasing the coal consumption for power generation in the power plant. It is estimated that when the leakage reaches 1% of the main steam flow, the leakage of the main steam pipeline valve can cause the coal consumption for power generation to increase by 2.8 to 3.14g/(kW·h).

Viti offers a full range of valve products and overall solutions for the harsh working conditions of thermal power plants, such as "high temperature and high pressure, high pressure difference, high erosion, and deep peak shaving".

Ii. Core Products and Solutions

1. High-pressure differential anti-erosion steam trap regulating valve - Overcoming the persistent problem of internal leakage

The steam trap is one of the most numerous valves in thermal power plants and operates under the harshest conditions. The Viti high-pressure differential steam trap regulating valve adopts a "three-stage pressure reduction" design of expansion, collision and offset:

- Volume expansion and pressure reduction: After the medium enters the valve chamber, the volume expands and the pressure decreases accordingly

- Collision pressure reduction: The medium first touches the extremely hard pressure-reducing sleeve, resulting in energy loss and further pressure reduction

- Countercurrent pressure reduction: The medium enters the pressure-reducing sleeve in a symmetrical direction. The high-energy fluids collide with each other, and the pressure can be reduced by 70%

In combination with the ultra-thick hard alloy surfacing sealing surface, when the valve is fully open, the valve core is completely protected by the pressure-reducing sleeve and is not eroded by the medium, fundamentally avoiding the occurrence of cavitation.

2. Multi-stage pressure reducing steam (feed water) control valve - Taming flash steam corrosion

For the flash evaporation and cavitation problems under high pressure difference conditions, the Viti multi-stage pressure reducing control valve adopts a multi-stage pressure reduction design (up to nine stages), decomposing the high pressure difference into multiple stages of stepwise pressure reduction to control the fluid flow rate and reduce vibration and noise. For valves with a capacity of over 1500Lb, forged valve bodies are preferred. It adopts a balanced valve core, ensuring even force distribution during the opening process. The opening of the labyrinth sleeve can be specially designed according to the working conditions, and is suitable for harsh working conditions or complex media.

3. High-pressure three-offset all-metal hard-sealed butterfly valve - Dual functions of regulation and shut-off

This product adopts the world's unique three-eccentric structure design, featuring bidirectional pressure resistance and zero leakage capability. Its maximum pound level can reach 2500Lb, and it is applicable within a temperature range of -196℃ to 850℃. The valve opens and closes flexibly, can quickly cut off the pipeline, and its performance is superior to that of gate valves. It has high regulating performance and can replace Globe type control valves. The sealing ring and the valve seat can be directly disassembled and replaced from the valve body as a set, enabling rapid on-site maintenance.

4. Minimum flow recirculation regulating valve for feed water pump - Safeguarding the safety of the "heart"

The feed water pump is known as the "heart" of the unit, and the minimum flow valve is the "protective device" of this heart. Viti adopts the "circulating convection labyrinth disc technology", which decomposes the high pressure difference step by step through the process of "impact - diversion - collision - pressure reduction", and ultimately controls the flow rate through the sealing surface within a safe range, fundamentally eliminating the destructive power of cavitation and cavitation.

Iii. Qualification Assurance: A1-level TS License +TSG Certification

The Viti Russia production base has officially obtained the Special Equipment Production License (TS certification) issued by the State Administration for Market Regulation, and is permitted to engage in the manufacturing of A1 and B grade metal valves for pressure pipelines. Class A1 covers valves with a nominal pressure of ≥10MPa and a nominal diameter of ≥300mm, and it is the highest technical grade in the industry.

At the same time, it has obtained the Special Equipment Type Test Certificate (TSG certification). The gate valve covers PN≤32.0MPa, DN≤600mm, and temperatures ranging from -20 to +625℃, while the butterfly valve covers PN≤16.0MPa, DN≤1000mm, and temperatures ranging from -20 to +425℃. Both are of the highest grade A1.

In addition, Viti has obtained three international system certifications: ISO 9001, ISO 14001, and ISO 45001. The entire chain from raw material entry, processing and manufacturing to finished product delivery has passed the dual tests of international standards and domestic regulations.

Iv. Performance Testimony

Viti products have been successfully applied to multiple large-scale projects, including the 2×1000MW ultra-supercritical heating renovation project of Guoneng Lingwu (608℃/5.67MPa), the 2×9F class gas turbine project of Huaneng Tai 'an, and the longest domestic heating renovation project of Huadian Wangting Power Plant (36.2km). It covers hundreds of power generation enterprises affiliated with China Energy Group, China Huaneng, China Datang, China Huadian, etc.

Conclusion

Viti - based on German technology, supported by Russian complete machine production, and guaranteed by A1-level TS/TSG qualifications, provides a full range of valve solutions from drainage, regulation to shut-off for the harsh working conditions of thermal power plants.