Method and system for recovering circulating water residual heat of thermal power plants

Abstract

The invention provides a method and system for recovering the circulating water residual heat of thermal power plants. The system comprises an absorption type heat pump, a turbine, a condenser, a basic heat supply network heater, a peak heater, an auxiliary pipe, auxiliary equipment and a coordination control and protection system, wherein the absorption type heat pump is used for recovering the residual heat of circulating water of the condenser and heating return water of a main heat supply network; the basic heat supply network heater is used for heating the return water of the main heat supply network, which is heated by the absorption type heat pump; the peak heater is used for heating the return water of the main heat supply network, which is heated by the basic heat supply network heater and conveying the return water to users of the heat supply network; the auxiliary pipe is connected with the turbine, the condenser, the absorption type heat pump, the basic heat supply network heater, the peak heater and the auxiliary equipment; and the running and the safety of all equipment in the system are controlled by the coordination control and protection system. The invention has the advantages that heat which is discharged by the circulating water of the condenser to the air is recovered by the absorption type heat pump, the heating and steam extraction energy level of the thermal power plants is integrated, the energy of the thermal power plants is saved, and the heat supply capability and economy of the thermal power plants are improved.

Description

technical field [0001] The present invention relates to the waste heat recovery technology of power plants, in particular to the waste heat treatment technology of circulating water, in particular to a method and system for recovering waste heat of circulating water in thermal power plants. Background technique [0002] The power generation methods of the power plant include pure condensation power generation, combined heat and power generation, etc. After the steam generated by the boiler of the pure condensing thermal power plant drives the turbogenerator to generate electricity, most of the heat in the discharged steam is taken away by the cooling water, so the thermal efficiency is low. Generally, the thermal efficiency of a pure condensing power plant with a single unit capacity of 200MW or more is only 35-40 %. Although the combined heat and power technology can improve energy utilization efficiency, there is still a large amount of heat exhausted by the steam turbine...

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Problems solved by technology

However, the actual heating capacity does not reach the design value, such as figure 2 As shown, the return water temperature of the heating network of the main network is 55°C. After two-stage heating, the temperature can only reach 132.7°C, which is lower than the designed 150°C.

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