拥有英文水污染监测英文文献

2021年1月20日发(作者：吃一堑长一智英文)
兰州交通大学毕业设计（外文文献）

The Besign of Oxidation Ditch Control System Based onPLC and
Kingview
Jie SU
College of Mechanical Engineering, Ningxia University
Yinchuan, China
Su5989703jie@

Xuejun Zhu
College of Mechanical Engineering, Ningxia University
Yinchuan, China
zhuxuejunnxu@

Abstract
—
With the exhaustion of water resources, the urban sewage circulation processing
has
become
an
indispensable
way
for
the
construction
of
an
environmental- friendly,
energy-saving
and
sustainable
society.
The
key
is
directly
determined
by
the
superiority
of
treatment
process
and
automatic
level
of
control
system.
For
instance,
there
is
a
sewage
treatment plant in Yinchuan city, which has the sewage treatment capacity of 50,000 t/d and
uses the oxidation ditch process. In this paper, we design an automatic control and monitoring
system for the sewage treatment plant. In the system, Siemens S7-300 PLC is a slave station.
It can be used to control field devices and collect variable data from sensors, including DO,
PH,
liquid
level,
flow,
and
MLSS,
etc.
The
upper
computer
uses
KingVIEW
software
to
exchange data with slave station, thereby realizing the centralized management.
Keywords
: Sewage treatment; oxidation ditch process; PLC; DCS;KingVIEW
I
、

INTRODUCTION
Water is a basis for the survival of human being, and is the foundation of all creatures. It
plays an important role in regulating global climate. But with the rapid economic and social
development and the further promotion of industrialization and urbanization, water resources
have become an important factor of restricting economic development[1]. By the end of 2010,
Chinese urban wastewater quantity is 133.45 million m3 per day but urban sewage disposal
capacity is only 102.62 million m3/d. The rate of urban sewage treatment is only 76.9%. The
general
situation
of
water
resources
is
worsening,
and
improving
the
capacity
of
sewage
treatment is extremely urgent.
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兰州交通大学毕业设计（外文文献）

In
the
sewage
treatment
process,
oxidation
ditch
is
the
core
of
biological
chemical
method and influences the quality of effluent water directly. Using the PLC controller with a
superior performance, a stable and reliable integrated automation system for sewage treatment
can be designed and has great significance. The configuration monitoring system can help the
sewage
treatment
process
to
realize
fully
automatic
control.
KingVIEW
with
industry
is
leading
HMI
and
object
oriented
environment
with
strong
graphic
network
function,
can
exchange
data
realtime
with
the
machine
and
other
computer
application
[2].
Through
the
communication
protocol
conversion
interface
I/O
Server,
it
is
convenient
to
connect
other
industrial
control
equipment.
Due
to
KingVIEW,
we
can
create
the
oxidation
ditch
process
section efficiently by using computer interface.
II
、

INTRODUCTION TO THE OXIDATION DITCH PROCESS
At present, biological chemical method is a way most frequently used in urban sewage
treatment.
Compared
with
chemical
treatment,
biological
treatment
method
for
the
sewage
processing is more economical, efficient and mature. It is to absorb and transform the harmful
substances in sewage water by the metabolism of microorganism. The oxidation ditch process
is typical in biological treatment method. It is a kind of connections between the front and the
cycle flow aeration ditch. It can also be called continuous circulating aeration which is a kind
of
activated
sludge
variant
[3].
Considering
the
stability
of
sewage
water
and
its
treatment
capacity between 30000 to 100000 m3 per day, we choose the Carrousel-3000 oxidation ditch.
It can fully embody the good treatment effect and its energy-saving characteristic of oxidation
ditch process [4], [5]. It has a thick grid, sewage pump room, ascension grid, aeration heavy
fine
sand
pool,
choose
pool,
anaerobic
pool,
oxidation
ditch,
eventually
pond,
contact
disinfection
pool,
backflow
sludge
pump
room,
the
sludge
regulation
ponds
and
sludge
dewatering, etc. The Carrousel-- 3000 oxidation ditch process section is shown in figure 1 and
its
flow
diagram
type
in
figure
2.
After
primary
treatment,
urban
sewage
water
flows
into
oxidation
ditch
with
decomposition
purification
and
finally
gets
to
the
stage
of
mud
water
processing.
The oxidation
ditch process
section is
the place for biological
treatment,
where
waste
water
and
the
biological
sludge
are
mixed;
table
aeration
machine
provides
suitable
dissolved oxygen levels for bacteria metabolism, help form alternately good oxygen, lack of
oxygen and anaerobic conditions in the trench and undertakes the main task of biochemical
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兰州交通大学毕业设计（外文文献）

treatment.


Figure 1Carrouse-3000l oxidation ditch process section


Figure 2Carrousel-3000 oxidation ditch process flow


Figure 3DCS control system structure based on PLC and the KingVIEW

III
、

THE OVERALL DESIGN OF CONTROL SYSTEM
As an object for control, the demand for oxidation ditchprocess section mainly centers on
data
collection
and
its
orderand
logic
control.
Thus,
PLC
is
chosen
as
the
slave
station
3
兰州交通大学毕业设计（外文文献）

inautomatic control system [6]. The system needs to realizemonitoring and automatic control
of
the
biochemical
treatmentprocess,
which
mainly
includes
the
control
of
table
aerationmachine, propeller and water electric weir. The DO value ismonitored and by the use
of soft measurement technology,BOD is estimated and the flow of water is monitored based
onthe value of DO, PH, ORP. Table aeration machine realizes itscontrol by taking dissolved
oxygen aeration as a controlvariable; propeller adopts switch control; water electric weirtakes
BOD
as
a
variable
to
realize
its
control.
According
to
thecharacteristics
of
the
Carrousel--3000
oxidation
ditch
processand
its
controlling
requirements,
we
can
design
a
DCS
controlsystem
in
line
with
the
idea
of

control
and
integratedmanagement
which is based on PLC and KingVIEW [7]. Asis shown in figure 3, the first level is Site layer,
mainlyincluding inspection instruments, the I/O interface device, andthe local control cabinet;
The second layer is PLCprogrammable controller, which can realize logic control basedon the
data collected from site and the logic relationship ofequipment operation; The third layer is
the remote monitoring(scheduling)
center, mainly
using industrial control
computer(IPC) to
monitor the real time parameters of process sectionand the working condition of equipments,
automatically
adjustthe
equipment
operation
and
realize
the
functions
of
alarmingand
interlocking. It can also display the dynamic real-time graph directly, make the trend analysis
and
show
and
print
the
historical
monitoring
data[8].
For
the
monitoring
system,
we
use
Yanhua
industrial
computer
IPC
as
the
master
station.
After
installing
the
KingVIEW
configuration software, we can set up a database. The SIMATIC S7-300 PLC is employed as a
slave station. In the oxidation ditch process period, the logic control of table aeration machine,
propeller and water electric weir is realized based on the data collected from site and the logic
relationship
of
equipment
operation.
Touch
screen
will
be
fixed
if
needed,
mainly
used
to
display the field
of process
parameters and configure control parameters, which can realize
the
manual
operation.
The
central
processing
unit
chooses
CPU315-2
DP.
It
has
strong
processing capacity and adopts modular design structure which has an easy configuration and
is
convenient
for
future
expansion.
Equipped
with
CPU
module
CPU315-2
DP,
we
need
PS307 power supply module 1 piece, CP343-1 comunication module 1 piece, 2 pieces of 32
points SM321 DI module, 2 pieces of 32 points DO module, 1 piece of SM322 8 road SM331
AI module [9], SIMATICTP270-10 touch screen. The data transmission is
mainly achieved
through
adopting
an
universal,
open,
high-speed
and
reliable
industrial
Ethernet
between
4
兰州交通大学毕业设计（外文文献）

master-slave
stand
[10].
By
installing
the
distributed
the
I/O
ET200,
it
makes
possible
communication
between
the
machine
with
the
field
under
equipment
and
intelligent
instrument, constituting the bottom profibus-DP. Figure 4, figure 5 and figure 6 are the wiring
diagram between PLC and the equipment, instrument, which are DI module, DO module and
the AI module of the wiring diagram respectively.


Figure 4oxidation ditch process section digital input module wiring diagram

5