Secondary reheating ultra-supercritical unit improved through subcritical coal-fired power generation unit

Abstract

The invention relates to a secondary reheating ultra-supercritical unit improved through a subcritical coal-fired power generation unit. At present, no secondary reheating ultra-supercritical unit improved through the subcritical coal-fired power generation unit exists. The secondary reheating ultra-supercritical unit comprises a condenser, a condensation water pump, a deaerator, a water supply pump, a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder and a main generator. The secondary reheating ultra-supercritical unit is characterized in that an ultra-supercritical boiler superheater, an ultra-supercritical back pressure machine, an ultra-supercritical boiler primary reheater, a No.0 high-pressure heater, a back pressure steam extraction type turbine, an ultra-supercritical boiler secondary reheater and a small power generator are further included; a third-stage high-pressure heater is connected with the No.0 high-pressure heater; the No.0 high-pressure heater is connected with the ultra-supercritical boiler superheater; the ultra-supercritical boiler superheater is connected with the ultra-supercritical back pressure machine; and the ultra-supercritical back pressure machine is connected with the No.0 high-pressure heater, the ultra-supercritical boiler primary reheater and the back pressure steam extraction type turbine through pipelines. The energy efficiency level of the existing subcritical power generation unit can be greatly improved.

Description

technical field [0001] The invention relates to a double-reheat ultra-supercritical unit, in particular to a double-reheat ultra-supercritical unit transformed with a subcritical coal-fired generator set, which belongs to the technical field of coal-fired power generation and is mainly used in subcritical coal-fired power generation. Coal generating units, especially suitable for subcritical units with a service life of more than 20 years. Background technique [0002] One of the characteristics of the development of modern thermal power plants is high parameters and large capacity. my country has vigorously developed subcritical units since the 1990s, and its capacity includes 300MW and 600MW, which account for most of my country's installed power generation capacity; 2000 At the beginning of the year, my country began to vigorously develop supercritical units with a capacity of 600MW; from 2006, ultra-supercritical units began to develop on a large scale in my country, and ...

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Problems solved by technology

In particular, the National Development and Reform Commission, the National Energy Administration and the Ministry of Environmental Protection jointly issued the "Notice on Printing and Distributing the Action Plan for Upgrading and Renovating Coal Power Energy Conservation and Emission Reduction (2014-2020)" (Fagai Nengli [2014] No. 2093) (hereinafter Referred to as the "Action Plan"), its requirements: by 2020, the average coal consumption for power supply after transformation of active coal-fired generating units will reach the level of 310g / kWh, and the average coal consumption for power supply of 600,000 kilowatts and above units (except air-cooled units) after transformation will reach 300g / kWh, the "Action Plan" puts forward more stringent requirements for the upgrading and transformation of existing coal-fired power units, and subcritical units with low energy efficiency become the primary targets of transformation. Due to the limitation of unit parameters, conventional technical transformation methods are adopted (such as steam turbine flow transformation and other measures) it is difficult to greatly improve the energy efficiency level of the unit. Therefore, it is a new idea to find a transformation method that can effectively improve the parameters of the subcritical unit

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