Steam energy cascade heat recovery utilization system for operation under full working conditions and working method

Abstract

The invention relates to a steam energy cascade heat recovery utilization system for operation under full working conditions and a working method. The system and the working method are mainly appliedto a heat supply unit. The system comprises a back pressure steam turbine, an absorption type heat pump and an air heater; a main steam turbine pumps air and supplies heat through a medium and low pressure communication pipe, and an air inlet of the back pressure turbine is connected to a heat-supplying and air-pumping pipe of the main steam turbine; heat supplying steam is used for driving the steam turbines to rotate, so that a power generator is driven to generate electricity, high-grade energy of the steam is recovered, and the generated electricity is incorporated into a plant power system; an exhausting drive absorption type heat pump of the back pressure turbine recovers low-grade waste heat. During a heating season, the absorption heat pump heats net water to supply heat to the outside; during a non-heating season, through switching of a three-way valve, the absorption type heat pump is used for heating air entering a boiler to achieve heat recovery. By adopting the system, operation of the back pressure steam turbine under the full working conditions and cascade use of the steam are achieved, coal consumption and a plant power consumption rate are decreased, and the economic performance of the unit is improved.

Description

technical field [0001] The present invention relates to the technical field of back pressure machine and heat supply, in particular, the present invention particularly relates to a steam energy cascade heat recovery utilization system and working method operating under all working conditions. Background technique [0002] my country's energy utilization efficiency is low, which seriously restricts my country's economic development and social progress. In the face of the country's major strategic needs for energy conservation and emission reduction, it is imperative to develop new technologies for efficient energy utilization and low emissions. In combined heat and power units, in order to improve energy utilization and realize cascaded utilization of energy, the main steam turbine is generally used to extract steam for heat supply. However, as the operating parameters of the main steam turbine are getting higher and higher, the temperature of the main steam turbine for heat...

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Problems solved by technology

However, the problem with this system is that the entire system invested, including the back pressure steam turbine and absorption heat pump, can only be used in the heating season, and the operating hours throughout the year are relatively low, which greatly affects the economic benefits of the system and does not give full play to its potential. own potential

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