This project belongs to the field of design and manufacturing of cogeneration equipment. 1. Project background With the increasing shortage of energy, saving energy, reducing consumption and increasing efficiency have become the path of vigorous promotion and development. In the field of thermal power, it is mainly reflected in aspects such as centralization of heating, rationalization of heating distribution, and efficiency of heating equipment. Improving the parameters of the heat-supply extraction turbine to improve the efficiency of the turbine and maximize the heat supply is an important means to make cogeneration efficient. To this end, Shanghai Steam Turbine Factory Co., Ltd. has developed a 565℃ high-efficiency 50MW extraction back-pressure steam turbine. Compared with the conventional 535℃ units on the market, the unit output has increased by more than 10%. 2. Main technical innovations The development of this unit relies on the new construction project of Nanjing Yudai Thermal Power Plant. It is the first time that an extraction back-pressure steam turbine has adopted 565℃ inlet steam parameters. The main innovations of this project are as follows: 1) For the first time, the parameters of a 50MW extraction back steam turbine will be increased to 565℃; if the inlet and exhaust steam pressures remain unchanged, the steam temperature will be increased from the conventional 535℃ to 565℃, and the average temperature of the cycle heat absorption will also increase accordingly, which will improve the cycle thermal efficiency of the unit. 2) Advanced overall thermal optimization platform, efficient flow passage design technology with variable reaction degree; the unit adopts AIBT design small diameter multi-stage reaction type instead of impulse type (For example, stage 10 replaces stage 6), and the flow efficiency is increased by about 4% to 5%;3) Modular design to meet user customization requirements; advanced finite element strength analysis technology and computational fluid dynamics analysis technology are used to enable the steam turbine to meet ultra-high intake parameters. For operating conditions, the double-layer cylinder structure design is adopted to reasonably distribute the load borne by the inner and outer cylinders, and the smaller temperature gradient and pressure gradient enable the unit to quickly start and stop and change the load; 4) Novel warm-up technology, flexible start-up and shutdown, etc.; use backward warm-up to start, and use the heating pipeline warm-up time to synchronously preheat the steam turbine, greatly shortening the start-up time of rated parameters, making the unit more flexible;3. Intellectual property rights Status and level Through research and development by technicians, this project has overcome key difficulties in the design process, and produced 1 patent and 1 paper. The successful development of a 565℃ high-efficiency 50MW extraction back-pressure steam turbine has filled the gap in the technology of 565℃ extraction back-pressure steam turbines in the domestic heating industry and laid the foundation for our company to develop and research ultra-high temperature extraction back-pressure heat supply units. 4. Promotion and application situation The 565℃ high-efficiency 50MW back-pressure steam turbine equipment has a simple structure, reliable operation, and a payback period of less than one year. In terms of dragging rotating machinery and equipment and optimizing energy-use systems of enterprises, the energy-saving effect is very significant. Relying on the 50MW extraction back-pressure turbine project of Huaneng Nanjing Thermal Power Plant, our company has successfully completed the development of a 565℃ high-efficiency 50MW extraction back-pressure turbine, and has achieved significant technological breakthroughs and extensive user praise in the heating industry of this power level., allowing our company to continue to sign back-type heating unit projects including Yufeng, Linggu, Shanying, Li Cultural Industry, Yingcheng, Haoyang, Taicang, etc. This project unit is the first time in the industry to adopt 565℃, which will drive further technological innovation in the industry, lead a new round of technical optimization of 50MW heating units, improve the technical capabilities of our company's heating units, and also contribute to low-carbon energy conservation in my country.