Drainage system for low-pressure heaters

Abstract

The invention provides a drainage system for low-pressure heaters. The drainage system comprises the No.7 low-pressure heater and the No.8 low-pressure heater which are positioned at the last two stages of a unit. A drainage outlet of the No.7 low-pressure heater is positioned in the bottom of a No.7 low-pressure heater shell. A drainage inlet of the No.8 low-pressure heater is positioned in the lower side of the horizontal symmetry axis of a No.8 low-pressure heater shell, and the drainage outlet is communicated with the drainage inlet through a pipeline. An adjustable ball valve is arrangedon the pipeline. The drift diameter of a valve core of the adjustable ball valve is the same as that of the pipeline in front of the valve and that of the pipeline behind the valve, and the bends of the pipeline are communicated through elbows. A drainage pump is arranged at the drainage outlet. A pressure sensor is arranged at the bottom in the No.7 low-pressure heater shell, and the adjustable ball valve, the pressure sensor and the drainage pump are connected with a controller. By changing the position of a drainage joint and the pipeline arrangement of the low-pressure heaters, the problemof poor drainage between the low-pressure heaters at the last two stages can be effectively solved, meanwhile the automatic adjustment of the water level can be realized, and the economic efficiencyof the unit can be improved.

Description

technical field [0001] The invention relates to the technical field of generating set drainage, in particular to a low-pressure heater drainage system. Background technique [0002] In the commonly used low-pressure heaters of thermal power units at various levels, the pressure difference on the steam side of adjacent surface heaters is mainly used to flow the water with higher pressure to the heater with lower pressure, and flow step by step until it is separated from the main condensate. Mixing, that is, the step-by-step drainage method, the system is relatively simple, and the drainage heat of the upper-stage heater can be returned to the heat recovery system, which can improve the economy of the unit. [0003] The low-pressure heaters arranged by the existing 300MW unit, among them, the low-pressure heaters located in the last two stages, No. 7 low-pressure heater and No. 8 low-pressure heater are set in the same shell, see the attached figure 1 , No. 7 low-pressure hea...

AI Technical Summary

Problems solved by technology

[0005] This application provides a low-pressure heater drainage system to solve the problem of poor drainage between the two low-pressure heaters at the end of the existing unit and reduce the economical efficiency of the unit

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