Control System Retrofits to Improve Plant Efficiency.pdf
文本预览下载声明
Babcock Wilcox 1
Control System Retrofits to Improve Plant Efficiency
T. Leung
Babcock Wilcox
Cambridge, Ontario, Canada
J. Peet
Babcock Wilcox
Cambridge, Ontario, Canada
Presented to:
Canadian Electrical Association
Thermal Generating Station Construction
and Commissioning Session
March 1995
Vancouver, British Columbia, Canada
BR-1589
Summary
The availability of powerful first principles type
models designed for PC-based computer hardware pro-
vides a simple and effective tool for the study of tran-
sients within power plants. All of the essential compo-
nents of the plant including the controls can be modelled
and the behavior of the plant to various transients can
be evaluated. This paper will address the use of such a
dynamic model to design an improved control strategy
for pulverized coal fired drum type boilers connected to
single reheat type turbine generators. Comparisons with
the current techniques will be used to quantify the ben-
efits and demonstrate the simplicity of the control meth-
odology.
Introduction
Utilities in North America are faced with a declining
margin between installed capacity and electrical demand.
Consequently, a greater proportion of units are required
to participate in middle load and peaking duty. This ap-
plies to the larger, more efficient plant and older, smaller
units which previously were base loaded. A utility’s abil-
ity to meet the system demand in the most cost effective
manner will be, to some degree, dependent on the load
range and maneuverability of the individual units. The unit
efficiency under cycling duty will depend on the degree
to which boiler and turbine efficiencies can be maintained
over the operating load range. The parameters which can
affect the unit efficiency during cycling operation or limit
the unit’s capability to cycle are:
1. Pressure and temperature control to the turbine
2. Extent of overfiring/underfiring in the boiler
3. Excess air and exhaust gas temperature leaving the
boiler
The paper w
显示全部