Ultra-supercritical secondary re-heating steam turbine set

Abstract

The invention discloses an ultra-supercritical secondary re-heating steam turbine set. The ultra-supercritical secondary re-heating steam turbine set comprises a first bearing box, an ultra high pressure-high pressure cylinder, a second bearing box, a medium-pressure cylinder, a third bearing box, a first low-pressure cylinder, a fourth bearing box, a second low-pressure cylinder and a turning gear box which are assembled on a rotor in sequence. The capacity of the steam turbine set is 1000-1300MW, the ultra high pressure-high pressure cylinder is of a cylinder combined structure, the pressure of a steam inlet of an ultra high pressure part is 30-35MPa, the temperature is 600 DEG C, the pressure of a primary re-heating steam inlet of a high pressure part is 10MPa, the temperature is 610-630 DEG C, the medium-pressure cylinder, the first low-pressure cylinder and the second low-pressure cylinder are respectively of a double-flow-division structure, the medium-pressure cylinder provides steam for the first low-pressure cylinder and the second low-pressure cylinder respectively through communication pipes, the pressure of a secondary re-heating steam inlet of the medium-pressure cylinder is 2.8MPa, and the temperature is 610-630 DEG C. The ultra-supercritical secondary re-heating steam turbine set has the advantages of being large in capacity, high in parameter, small in occupied space, low in investment cost, stable and reliable in operation and obvious in economical benefit, saving energy, reducing consumption and the like.

Description

technical field [0001] The invention relates to a steam turbine unit, in particular to an ultra-supercritical twice-reheated steam turbine unit. Background technique [0002] my country's power production is dominated by coal power, and this situation will exist for a long time. It has always been an important and urgent task for the development of my country's electric power industry to adopt advanced technology to improve the efficiency of coal-fired units, realize energy saving and consumption reduction, and reduce environmental pollution. Ultra-supercritical steam turbine unit with secondary intermediate reheat refers to the ultra-supercritical steam turbine unit with main steam pressure above 25.0MPa and main steam temperature or / and reheat steam temperature at 580°C or above. For ultra-supercritical steam turbine units, the efficiency can be increased by about 1.5%, and the economic benefits are significant. The development of ultra-supercritical steam turbine units w...

AI Technical Summary

Problems solved by technology

[0004] 1. The capacity and steam parameters of the unit are very low, resulting in high energy consumption, low power generation efficiency, serious environmental pollution, and poor economic benefits;

[0005] 2. Considering factors such as cylinder forming structure, forming materials, manufacturing cost and operating parameters, the overpressure cylinder and high pressure cylinder of the unit are of separate structure, and the structure of the whole unit is loose and bulky, resulting in a large footprint of the unit The engineering construction cost of the power plant is very high;

[0006] 3. The regenerative steam extraction system to improve the thermal economy of the unit (that is, to increase the average temperature of the working fluid in the process of heat absorption in the boiler) is 8 levels. Although it saves equipment investment, it sacrifices thermal efficiency to a certain extent. This not only Increased energy consumption and environmental pollution, and also affected the power generation of the unit;

[0007] 4. The maximum continuous evaporating capacity of the boiler (ie BMCR) adopts 100% bypass capacity, not only the system is complicated, the investment cost is high, but also the pressure and flow distribution in the boiler cannot be controlled. The exhaust steam temperature of ultra-high pressure, high pressure and medium pressure is low It will run over temperature under load, and the working conditions that can be adapted are limited

Images