Boiler Drum Level Control

Problem in Boiler Drum Level Control with YS170 and SLPC:

  • In the YS170 and SLPC, single-element control needs to be configured within the user program.
  • The YS1700, however, offers the primary direct mode so that the user program can switch on and off single-element control by changing a parameter.

Three-element Control:

  • Disturbances in drum level are caused by fluctuations in main steam flow.
  • Figure 1 shows a typical drum level controller, which measures the drum level (1), main steam flow (2), and feedwater flow (3) and manipulates the feedwater control valve to regulate the drum level. This is three-element control.
  • This three-element controller is a so-called cascade controller in which a drum level control unit is cascaded into a feedwater flow control unit.

Single-element Control:

  • During startup of a boiler, both the feedwater and main steam flow rates remain below the measurable ranges, and this makes the three-element control with a level controller and flow controller unstable.
  • In such cases, it is effective to use single-element control in which the feedwater controller is bypassed and the drum level controller directly controls the feedwater control valve.

Cascade function(CSC)

產業別

相關產品&解決方案

YS1700

YS1700可編程指示調節器可以通製運行用戶程序為各種應用進行定制,並通製橫河電機的專有技術、用戶友好性和可擴展性提高可靠性。

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