A solution for clean coal power, Sanicro® 25 boosts the world’s most energy-efficient thermal power unit

Exterior view of the second phase of Shenergy Pingshan Power Plant Phase II

Designed for clean and efficient coal-fired power boilers, it perfectly copes with extremely high temperatures and contributes to improved energy efficiency.

On 16 December 2020, the construction unit of the Shenergy Pingshan Power Plant Phase II was successfully connected to the power grid. Following that, all the main and auxiliary equipment began operating stably and reliably, laying a solid foundation for the next 168-hour trial operation. As a supercritical double reheat unit of high and low split shaft arrangement with the world’s largest unit capacity, each aspect of the project construction garnered attention from the industry worldwide. Among the elements, the boiler tubes used in the high-temperature reheater and high-temperature superheater were provided by Sandvik.

Project introduction - the world’s most energy-efficient thermal power unit

The Shenergy Pingshan Power Plant (SPPP) Phase II 1350MW (megawatt) dual-shaft high and low double reheat unit project sets the standard as a model innovation that is energy-saving and reduces emission. SPPP was commissioned on 12 October 2016, and will be operational in 2021 as planned.

The project aimed to build a thermal power unit using the largest unit capacity but with the lowest energy consumption in the world. It created a dual-shaft double reheat generating unit with a high and low arrangement, a first in the world, raising the steam temperatures during both single and double reheat to 630°C. At the same time, a series of energy-saving and emission reduction innovative technologies with proprietary intellectual property rights and patents owned by Shenergy Technology, a subsidiary of Shenergy Group, was adopted. The unit’s expected coal consumption of power supply is estimated to be 251g/kWh, greatly enhancing the economy of several load units to ensure safety, efficiency and stable operations.

After the completion and operation of the project, the full-load efficiency is now able to reach 48.92%, making it the most efficient and cleanest super-critical coal-fired power generating unit in the world. It will chart the course for the efficient and clean development of coal power at home and abroad, and will lay a solid foundation to the goal set by the National Energy Administration in China, which is to “strive for a net efficiency over 50% in coal-fired power generation in terms of clean combustion of coal and efficient power generation by 2030”.

The project perfectly demonstrates the future development of super-critical technology (650°C-700°C) with higher parameters and high-temperature tube materials. In this case, Sanicro® 25 was chosen as the boiler tubes material due to its superior quality and innovative characteristics which perfectly tackled the challenge of ultra-high temperatures.

Sanicro® 25 austenitic stainless steel, an excellent choice for boiler tubes

Coal_power_plant.jpgSandvik has over 50 years of experience as a supplier of high-quality stainless steel tubes for power plants and more than 150 years of knowledge in innovative steel production and R&D. Sanicro® 25, used in the reheater and superheater of the boilers in the SPPP Phase II project, is most likely the best-performing austenitic stainless steel material for boiler tubes in the current market.

Sanicro® 25 is an austenitic 22Cr25NiWCoCu stainless-steel material designed for clean and efficient coal-fired power plant boilers, which is characterized by extremely high creep resistance, excellent oxidation resistance and structural stability, as well as sound machinability and weldability. It can effectively handle metal temperatures of up to 700°C and higher pressures, such as 35 MPa (5000 psi), thereby helping customers boost the efficiency of ultra-supercritical boiler safely and reliably.

Innovative product to propel energy-saving and emission reduction

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Sanicro® 25 was officially launched in 2016 in China. After years of R&D and production efforts, the material became increasingly mature, which has resulted in landmark project orders locally. Apart from the SPPP Phase II project, the High-temperature Sub-critical Xuzhou project also chose Sanicro® 25 as the material for its boiler tubes.

Introduction to the High-temperature Sub-critical Xuzhou project:

With reference to the state promulgation and implementation of the Action Plan 2014 -2020 for Upgrading and Transforming Coal Power Energy Conservation and Emission Reduction, Shanghai Shenergy Power Technology Co., Ltd., based on innovative research, proposed the “600°C Sub-critical Unit Heating Transformation Technology”. The technology aims to further reduce coal consumption and maintain the long-term efficient operation of the unit, alongside the additional benefits including reduced unit starting energy consumption and operation costs.

It was successfully applied in the transformation of the 320MW sub-critical unit of the power plant of Xuzhou China Resources Power Co., Ltd. and the unit was operational on 10 August 2019 after passing a 168h trial operation. Tests from a third party showed that significant results were achieved, with a reduction of more than 35g/kWh of coal consumption for power supply underrated running conditions.

Today, coal-fired power plants rely on technological advances to produce cleaner energy, spawning innovations of materials to meet harsher environmental requirements. Sanicro® 25 enables your energy production to keep ahead of times, thereby increasing temperatures to 620°C, 650°C or even 700°C. The efficiency of coal-to-power conversion is continuously improved by increasing the temperatures and pressures of the boiler, which not only saves money in the entire life cycle of the boiler but also reduces coal consumption and emissions.

Sanicro® 25 helps you meet the harsh demands of coal-fired energy, and powers the technological innovation of energy-saving and emission reduction. So let’s bring on the heat!