Method for determining and recycling waste heat of boiler smoke by using phase change heat exchanger

Abstract

The invention relates to a method for determining and recycling waste heat of recycle boiler smoke by using a phase change heat exchanger. The method comprises the steps of (1) calculating the waste heat absorbed from the boiler smoke by the phase change heat exchanger; (2) calculating the steam extraction amount of a NO. 8 low pressure heater and a NO.7 low pressure heater after the phase change heat exchanger heats part of condensed water; (3) calculating the additional generating capacity after the steam extraction amount of the NO. 8 low pressure heater and the NO.7 low pressure heater is reduced for power generation; (4), calculating the waste heat saved energy of the boiler smoke by the phase change heat exchanger. The waste heat of the boiler smoke is recycled by the phase change heat exchanger and is used for heating the condensed water before the condensed water enters the NO. 8 low pressure heater at a pump outlet, the heated condensed water is combined into a condensed main pipeline at the outlet of the NO. 7 low pressure heater, and the reduced part of steam extraction amount is used for power generation, thus increasing the power of a power generator and reducing the consumption of burning coal.

Description

technical field [0001] The invention belongs to the technical field of thermal power generation and energy saving, in particular to a determination method for recovering residual heat of boiler flue gas by using a phase-change heat exchanger. Background technique [0002] The current boiler exhaust gas temperature is designed according to the classic design specifications for controlling acid dew corrosion conditions, and the calculation of the exhaust gas temperature has left room for equipment protection. However, with the prolongation of the operation time, the exhaust gas temperature increases due to the local dust accumulation of the equipment. When the operating exhaust gas temperature is 145 °C, it is 40-50 °C higher than the acid dew point temperature. With the intensification of competition among enterprises and the increasingly stringent requirements for energy saving, emission reduction and environmental protection, the exhaust gas temperature is further reduced, ...

AI Technical Summary

Problems solved by technology

However, there is no specific method for determining the energy saving value of recovering boiler flue gas waste heat by using the phase change heat exchanger, and the determination of the energy saving value is helpful for guiding the operator to adjust the operation mode of the phase change heat exchanger and recover the waste heat of the flue gas to the maximum extent. heat, has great guiding significance

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