Control system and control method for starting high-pressure heater in advance

Abstract

The invention relates to a control system and a control method for starting a high-pressure heater in advance. The control system can make full use of steam heat, and accurately controls the steam supply mode of the high-pressure heater through the cooperation between a temperature sensor and a controller. Before a boiler is ignited, steam supply heating is performed on the high-pressure heater No. 2 by an auxiliary steam system of an adjacent machine to increase the water feeding temperature of the boiler, and the wall surface of a heating surface of the boiler is increased by water change toprevent scale falling off due to too high increase speed of the wall temperature when steam flows through a superheater and a reheater after water plugs in a superheater and a reheater are removed when the steam temperature is about 100 DEG C after the boiler is ignited; and after the boiler is ignited and before a steam turbine starts to turn, the high-pressure heater No.2 is used to absorb heatof steam on a high-pressure by-pass to further increase the water feeding temperature and effectively recover the heat of the boiler before grid connection, so that on the one hand, the heating speedof the boiler is increased, and the start-up time is shortened, and on the other hand, the amount of steam discharged to a cold end is reduced, and the loss of a cold source during the start-up process is reduced.

Description

technical field [0001] The present application relates to the field of supercritical thermal power, in particular to a control system and control method for early starting of a high-pressure heater. Background technique [0002] In the thermal power industry, the feed water entering the boiler is usually heated to a certain temperature in advance to quickly start the boiler heating, so that the hot water steam can quickly meet the start-up requirements of the corresponding steam turbine, such as temperature, pressure and other parameters. [0003] Usually, the advance heating of boiler feed water is usually realized through high-pressure heaters, and the heat source for high-pressure heaters can usually be provided in the following ways: [0004] 1. Auxiliary heat source; for example, the document CN203421668U. In this patent document, although the auxiliary steam of the adjacent machine can be used to heat the feed water temperature, problems such as the temperature rise ra...

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Problems solved by technology

[0004] 1. Auxiliary heat source; for example, the document CN203421668U. In this patent document, although the auxiliary steam of the adjacent machine can be used to heat the feed water temperature, problems such as the temperature rise rate of the feed water and the end difference of the high-pressure heater are not considered, and no specific auxiliary steam and temperature are given. The steam supply timing of high-side steam makes the utilization rate of auxiliary steam and high-side steam low, and may even affect the safe and stable operation of the entire system

[0005] 2. High-side steam; for example, in the document CN105605551A, high-side steam is used to heat the feed water temperature and supply steam to several high-pressure heaters at the same time. In addition to the above problems, when the high-side steam enters the high-pressure heater at the same time, the high-pressure heater is The cold state causes the temperature of the high-pressure heater to rise suddenly, and there are also safety issues

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