Heating network draining system for circulating fluidized bed cogeneration unit under cylinder cutting working condition

Abstract

The invention discloses a heating network draining system for a circulating fluidized bed cogeneration unit under a cylinder cutting working condition. The heating network draining system solves the problem of how to take into account the safe operation of the unit and avoid the waste of heat energy under the condition that an existing cogeneration unit of a circulating fluidized bed boiler is used for cutting off part of low-pressure cylinders. A draining cooling heat exchanger is adopted to exchange heat of heating network draining water of a heat supply head station to heating network circulating water return water, then the cooled heating network draining water is conveyed to a heating network condenser for flashing to achieve the purpose of reducing the amount of flash steam, namely,it is ensured that a certain amount of condensed water with low temperature enters a main machine steam exhaust device, a main machine condensate pump is met and maintained at a normal working condition, the cooling effect of a cold slag device of the circulating fluidized bed boiler is ensured, the heat of the heating network draining water of the heat supply head station is exchanged to the heating network circulating water return water, the part of energy is fully utilized in a heat supply system, the heat supply cost is reduced, and the heat and the condensed water are newly and evenly distributed in the whole cogeneration heat supply unit.

Description

technical field [0001] The invention relates to a cogeneration heat supply unit, in particular to a heat network drainage system of a circulating fluidized bed boiler generating unit under the working condition of removing part of the low-pressure cylinder of the steam turbine during the winter heating period. Background technique [0002] The combined heat and power power generation and heating units using circulating fluidized bed boilers generally need to operate at 50% of the rated power generation load for 4-5 months during the winter heating period; in order to make the generating units achieve low energy consumption under partial load The power plant usually adopts the operation method of cutting off part of the low-pressure cylinder of the generator set. This operating condition of the generator set is called the low-pressure cylinder cut-off condition (or called the cylinder cut-off condition); When running under working conditions, during the heating period, the st...

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Problems solved by technology

[0003] The invention provides a heat network drainage system of a circulating fluidized bed cogeneration unit under the condition of cutting cylinders, which solves the problem of how the existing cogeneration units using circulating fluidized bed boilers can cut off part of the low-pressure cylinder. Taking into account the technical issues of safe operation of the unit and avoiding waste of heat energy

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