Industrial water replenishing and deoxidizing system and method for low-pressure cylinder cutting unit

Abstract

The invention discloses an industrial water replenishing and deoxidizing system and method for a low-pressure cylinder cutting unit, and belongs to the technical field of industrial water replenishing and deoxidizing systems for steam turbine cylinder cutting units. The system comprises a low-pressure cylinder and an intermediate-pressure cylinder, the low-pressure cylinder is connected with a condenser, steam exhaust of the intermediate-pressure cylinder is connected with a deaerator, the deaerator is further communicated with a first heater, and the heater is communicated with the condenser. Condensed water in the condenser enters the deaerator to exchange heat with steam and enters a steam turbine water supply system when the unit is in a cylinder switching operation condition. According to the invention, the temperature of the condensed water is increased by utilizing the intermediate discharge steam extraction, the inlet water temperature of the deaerator is increased, meanwhile, the temperature of the condensed water condensed in the heater is further reduced by utilizing the built-in drainage cooling section of the heater, then the condensed water is introduced into the water-water heat exchanger to heat industrial replenished water, and then the condensed water is discharged to the condenser for flash evaporation, so that thermal deaeration is realized; drain water of the heater is discharged into the lower portion of a condenser hot well to reheat condensed water again, the supercooling degree is eliminated, and the best effect of deoxygenization of the condenser is achieved.

Description

technical field [0001] The invention relates to an industrial water replenishment and deoxygenation system and a deoxygenation method for a low-pressure cylinder cutting unit, and belongs to the technical field of the industrial water replenishing and oxygen removal system for a steam turbine and cylinder cutting unit. Background technique [0002] After the industrial steam supply unit cuts off the low-pressure cylinder of the steam turbine, the large-flow industrial extraction steam will not return to the condensate water system. The condensate water system needs to replenish a large amount of chemical water. The temperature of the chemical water is low and the oxygen content is very high. There is no exhaust steam heating of the steam turbine after the unit, and the oxygen removal effect is poor. The condensed water entering the recuperation system has a very high oxygen content, which brings a huge risk to the safe operation of the unit. At the same time, after the low-p...

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Problems solved by technology

[0004] The middle row extracts steam to make up the condensed water for bubbling and deoxygenation. Due to the high degree of superheat of the middle row steam, when exchanging heat with the condensed water in the hot well, a large amount of boiling occurs in the cooling water in contact with the steam. The steam generated by the boiling The thermal resistance is very large. On the one hand, it seriously affects the heat recovery effect; on the other hand, part of the steam is directly discharged into the vapor phase space above the hot well in the form of bubbles, which increases the heat load of the condenser accordingly, and this part of the heat is eventually circulated. The water is taken away, resulting in poor economy of the unit. At the same time, the steam carried in the condensed water enters the condensate pump through the pipeline, which is more likely to cause cavitation of the condensed water pump, which brings safety risks to the operation of the unit.

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