Flue gas expander

1. overview

The flue gas expander is a core equipment in the energy recovery unit used in the catalytic refining unit of a refinery. It utilizes the expansion of high-temperature waste gas with a certain pressure generated during the process to drive the main fan or generator, achieving the goal of reducing device energy consumption.The application of flue gas expanders to recover high-temperature flue gas energy in catalytic cracking units of refineries began in the 1950s. It has been 53 years since the first single stage cantilever axial intake flue gas expander was put into industrial application in the United States in 1963. The first YL3000 flue gas expander independently jointly developed by Sinopec Engineering Construction Company (SEI, formerly Beijing Design Institute), Petrochemical Equipment Company and the Institute of Engineering Thermophysics of the Chinese Academy of Sciences was successfully put into operation at Fushun No.2 Petrochemical Plant in 1978. After more than 30 years of unremitting efforts, the YL series flue gas expander has achieved the goal of design and development, testing, application, development, improvement, and serialization. Its widespread application in catalytic cracking units not only reduces energy consumption and brings considerable economic benefits to users, but also promotes scientific research and production applications in related fields such as gas-solid separation technology, high-temperature alloy materials, wear-resistant coating materials, unit control, monitoring and online diagnostic expert systems. It promotes the wide application and deep development of advanced technology, new materials, on-line monitoring and planned maintenance of units in the field of rotary machinery in oil refinery. 

FCC energy recovery unit is usually composed of flue gas expander, main fan (axial flow or centrifugal compressor), steam turbine, electric/generator, gearbox, oil system and instrument control system. According to unit configuration, it is usually divided into three units (flue gas expander + main fan + electric/generator), four units (flue gas expander + main fan + steam turbine + electric/generator), and direct generator units (flue gas expander + electric/generator).

2. Specification and model

Specifications and technical parameters of YL flue gas expander

3. Technical quality level

¡ôFully independent intellectual property rights, different from the design philosophy of foreign manufacturers

¡ôThe design and manufacturing level has reached the forefront of the world

¡ôSingle stage insulation efficiency ¡Ý 83%, double stage insulation efficiency ¡Ý 86%

¡ôThe rigidity of the rotor is strong, and the dynamic performance of the rotor is stable

¡ôSemi rigid shell, guided expansion, strong ability to bear pipeline capacity and torque

¡ôVertical split, cantilever rotor structure, suitable for high temperature conditions

¡ôComplete separation of hot and cold components

¡ôThe best wear-resistant coating "Great Wall No.1" wear-resistant coating by plasma spraying and "Great Wall No.33" wear-resistant coating by detonation spraying can adapt to harsh working conditions and well protect the surfaces of moving and stationary blades and shrouds

4. Market performance

By the end of January 2023, more than 300 flue gas expander have been delivered to customers, which exceeds the total number of other manufacturers in the world, accounting for 60% of the total production of flue gas expander in the world, accounting for more than 90% of the domestic flue gas expander market.

5. Expanding applications in new fields

Bohai Equipment Lanzhou Petrochemical Equipment Company has expanded and applied the mature design and manufacturing technology of the YL flue gas expander to other fields, successfully developing YLX nitric acid tail gas turbine, HP synthesis gas expander, and YLM coal chemical flue gas expander. Especially the YLX11000A nitric acid tail gas turbine was successfully applied to the 270000 ton/year nitric acid plant of Jilin Cornell Chemical Industry Co., Ltd. in October 2013, which is one of the largest nitric acid plants in China.