Energy-saving system for adopting electric heat pump to deeply recycle smoke waste heat of thermal power plant for centralized heating

Abstract

The invention discloses an energy-saving system for adopting an electric heat pump to deeply recycle smoke waste heat of a thermal power plant for centralized heating and belongs to the technical field of recycling and utilization of smoke waste heat of boilers of thermal power plants. High-temperature smoke and circulating water make direct contact with each other for countercurrent flow heat exchange through a smoke waste heat recycling tower, the electric heat pump is indirectly connected with the circulating water through an anti-corrosion efficient water plate heat exchanger; return waterof a heating network enters the electric heat pump for indirect heat exchange with high-temperature circulating water through the anti-corrosion efficient water plate heat exchanger; the electric heat pump adopts electric energy in the power plant as a driving heat source, and if the temperature of the return water, which is heated through the anti-corrosion efficient water plate heat exchanger and the electric heat pump, of the heating network meets the requirement of supply water temperature, the return water is delivered to the heating network; and if the temperature of the return water ofthe heating network is lower than the required supply water temperature, the return water is delivered to a heating network heater to be further heated. By means of the energy-saving system, the energy utilization ratio is improved, the smoke waste heat recycling and desulfuration integrated function is achieved, emission of pollutants is reduced, the heating capacity of the thermal power plant is enhanced, and the environmental influence of the thermal power plant is reduced.

Description

technical field [0001] The invention belongs to the technical field of boiler flue gas purification and flue gas waste heat recovery and utilization in coal-fired thermal power plants, and in particular relates to a high-efficiency flue gas waste heat recovery that uses electric heat pump technology to use flue gas waste heat for centralized heating and simultaneously has a desulfurization function system. Background technique [0002] The design exhaust temperature of power plant boilers in my country's coal-fired thermal power plants at this stage can reach about 130 ° C ~ 150 ° C, and the potential for waste heat recovery is huge. The latent heat of gasification in the flue gas can be fully recovered by using the flue gas waste heat recovery tower with a direct contact heat exchanger as the main body to spray and condense the low-temperature flue gas. At the same time, during the heat exchange process, the SO carried by the flue gas 2 , SO 3 It will be dissolved in the...

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Problems solved by technology

[0003] On the other hand, the combined heat and power unit operates in the mode of "heating power", which leads to the thermoelectric coupling problem of the unit: during the low power load period, the unit generates excess power, but during the power load peak period, the power generation capacity is insufficient, which is not conducive to solving the problem. The peak-to-valley difference in power load causes the unit to lose its peak-shaving capability, which cannot meet the current requirements of thermal power peak-shaving in my country

At present, the heat pump heating system mainly composed of absorption heat pump units in thermal power plants is restricted by the steam extraction parameters of the steam turbine during operation, and the heating efficiency is low, so it cannot effectively realize thermoelectric decoupling

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