2015 International Conference on Industrial Instrumentation and Control (ICIC)
College of Engineering Pune, India. May 28-30, 2015
Automation of shell and tube type heat exchanger
with PLC and LabVIEW
Tushar V. Bhaskarwar,∗ Shripad S Giri∗ , R. G. Jamakar†
∗ Student, † Assistant
Professor
Instrumentation Engineering, S.G.G.S. Institute of Engineering & Technology, Nanded – 431606, India.
E–mail: ∗ bhaskar.tushar90@gmail.com.
Abstract—The paper focuses on implementing the automation
of a shell and tube type heat exchanger control system through
number of tools such as PLC, SCADA, OPC, LabVIEW and
internet. In this paper, PID method is implemented on Allen
Bradley Micrologix-1200C PLC. The RSView-32 and LabVIEW
as a SCADA has been used for graphically monitoring and
controlling. Various performance parameters have been found
out from the results comparison with MATLAB and PLC. The
improvement in project data analysis is successfully done through
the integration of PLC with LabVIEW. The PLC-SCADALabVIEW control loop is implemented with the functionalities
such as, set point modifications, data logging facility, real time
data examination and exportation of data with Microsoft-Excel.
For getting the signals from PLC to LabVIEW we have used
enhanced conventional SCADA based control system with PLC
as well as NI-OPC server extensively. The remote monitoring
and control of process parameters is done using LabVIEW web
publishing tool or remote panel manager. GSM (Global system
for mobile communication) modem has been used for sending the
SMS by using LabVIEW (Short Messaging Service) on mobile,
if any hazardous situation occurs. The integration of automation
can be enhanced further more with android mobile application
also with the help of LabVIEW dashboard application.
introduction of OLE for process control (i.e. OPC) has also
simplified the control system interfacing [3]. So The OPC is
an open process protocol in which any application can speak
with any other applications through an OPC network.
II. SHELL AND TUBE TYPE HEAT EXCHANGER
In the process industries, there is various uses of heat
transferring elements for that pupose heat must be transferred
by emission, by the mixing of hot and cold fluids or most frequently, by conduction through the walls of a heat exchanger.
A shell and tube heat type exchanger is most frequently
used device for heat exchange. It is the most common type
of heat exchanger in large chemical processes and other oil
refineries, and is suited for higher pressure applications. The
main purpose of a heat exchanger system is to transfer heat
from a hot fluid to a cooler fluid, so temperature control of
outlet fluid is of prime importance [5].
Index Terms- PLC, PID, OPC, LabVIEW, Internet
I. I NTRODUCTION
Programmable logic controllers (PLCs) are used in every
part of industry for enhancement and increase the production.
In place of various relays used in industry, a single PLC can
be programmed as a replacement. These older automated
system would used lots of relays. Basically, the PLC is a
programmable logic controller used as an assembly of solidstate digital or analog logic elements designed to make logical
decisions and provide appropriate outputs [1]. SCADA stands
for supervisory control and data acquisition which offers
graphical and visual representation of process parameters
even from the remote places. It provides the possibility of
monitoring as well as controlling of process parameters
through GUI (Graphic user interface) [2]. Programmable
Logic Controller has an ability to talk with SCADA RSVIEW32 by tagging the PLC variables to SCADA. In various case
studies and literatures survey many results are found that in
different applications, combination of PLC and SCADA are
used for better results. Before an OPC (Open process control)
each application had its own driver and their own proprietary
data paths, so during interoperability there is a problem for
third party application to access data from other devices. The
978-1-4799-7165-7/15/$31.00 ©2015 IEEE
Fig. 1. Shell and tube type heat exchanger
Heat exchangers are built for efficient transferring heat from
one fluid to another. The hardware structure of heat exchanger
system is as shown in figure 1.
The shell and tube heat exchanger provides a comparatively
large ratio of heat transfer area to volume and weight.These
shell and tubed type heat exchanger are made of very large
sizes, these easy to construct and mechanically rugged in
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construction. They provides large surface area for heat transfer
with wide range of sizes. The shell and tube type heat
exchanger are easy for maintenance and reasonably low cost.
As its name implies, this type of heat exchanger consists of a
shell (a large pressure vessel) with a bundle of tubes inside it.
One fluid runs through the tubes, and another fluid flows over
the tubes (through the shell) to transfer heat between the two
fluids [6]. The set of tubes is called a tube bundle, and may
be composed of several types of tubes: plain, longitudinally
finned, etc.
III. PROCESS INTRODUCTION
Our aim has to control the temperature of cold water outlet
of shell and tube type heat exchanger process. In this work
Allen Bradley Micrologix 1200C PLC used which has analog
input/output card consisting of two analog inputs and two
analog outputs. Since a system consist of single input single
output, we have been controlled only one parameter i.e.,
controller valve closing of heat exchanger process. In addition
to above, PID block has been added in ladder programming for
tuning the controller valve output. The manipulated variable
has the steam flow rate through the control valve. As per the
changes in the process temperature and the settings of P action,
I action and D action, the output of the PID block is calculated
and the steam valve opening will changes to maintain the water
temperature. The functional block diagram of process is shown
below in figure 2. Then we have tagged the addresses of ladder
logic parameter to the RSVIEW32 SCADA and checked the
results graphically. We have shown the set point for cold
water temperature, process value, controller valve closing (in
percentage) and P, I, D values of PID controller on SCADA.
Fig. 2. Functional block diagram of experimental setup
For better graphics user interface, we have been used
RSVIEW32 SCADA along with a LabVIEW. The monitor
screen pictures of RSVIEW SCADA is shown in figure 3. The
PLC is then interfaced with LabVIEW by an NI-OPC server.
Then build up one SCADA on LabVIEW panel and tagged
the addresses of ladder programming using data binding block
in LabVIEW. After inserting all the details in LabVIEW we
Fig. 3. Screen shot of RSView32 front panel for heat exchanger process
have successfully run the process. After acquiring the details
through NI-OPC server into LabVIEW we have automated the
process i.e. remotely controlled and monitored the front panel
of LabVIEW.
In this project web publishing tool and remote control
panel block is used in LabVIEW for publishing the LabVIEW
block diagram window on the web. Also we have flexibility
for getting SMS (Short Messaging Service) on mobile by
using GSM (Global system for mobile) module which has
interfaced with LabVIEW. So we have successfully observed
that LabVIEW is more suitable for HMI than RSVIEW-32
because of flexibility and versatility with any applications.
Now another aspect is that, we have consider PLC as interface
device with field side, and inserting or setting PID values
is done by LabVIEW so we have found that LabVIEW is
more suitable than PLC because we can give P, I, D values in
LabVIEW in decimal points which is not applicable in PLC.
The main advantage by using LabVIEW is ability to change
desirable data rate, even in terms of micro-seconds also.
The main advantage of LabVIEW has capability of data
transmission in terms of micro-seconds.
For better GUI we then used RSVIEW32 SCADA along
with a LabVIEW. The screen shot of RSVIEW SCADA is
shown in figure 3. The PLC is then interfaced with LabVIEW
by an NI-OPC server. Then build up one GUI or SCADA on
LabVIEW panel and tagged the addresses of ladder programming using data binding block in LabVIEW. After inserting
all the details in LabVIEW we have successfully run the
process. After acquiring the details through NI-OPC server
into LabVIEW we have automated the process i.e., remotely
controlled and monitored the front panel of LabVIEW.
IV. OPC PROTOCOL
The OLE for Process Control (OPC) standard, proposed
in the second half of the 1990s, is novel process control
architecture. The motivation behind OPC is to develop a
standard mechanism for communicating to numerous data
sources, either devices on the factory floor, or a database in
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a control room [7]. Fig. 4 shows the various devices can be
connected through OPC (OLE for process control network).
For configuring PLC as new DDE/OPC connection with NIOPC server [8], we have to use RS Linx of Rockwell software.
For communicating this, we have to use topic configuration
option in RS Linx and just select PLC program and say apply.
single output type so, the readings has been taken by putting
controller in manual mode. table 1 shows the open loop
readings of process. First put controller (Globe valve) with
60% opening and noted the temperature saturation at output
side. Similarly reading has been taken for 75% control valve
opening. Now for finding out the transfer function of system
we have taken input/output data in data logger of RSVIEW
SCADA in excel format. The transfer function for the shell and
tube type heat exchanger process is obtained using maximum
slope method [9]. The transfer function is given in equation
(1) is obtained from the following experimental data.
Step Size
Control ValveOpening
Cold Water InletFlow Rate
Hot Water Inlet Flowrate
Cold Water InletTemperature
Hot Water InletTemperature
Readings
First Reading
60%
60%
160 lph
300 lph
31 Deg. Celsius
70 - 80 Deg Celsius
TABLE I
Second Reading
75%
75%
160 lph
300 lph
31 Deg. Celsius
70 - 80 Deg Celsius
E XPERIMENTAL DATA INLET PARAMETER CONDITION
Fig. 4. shows the connection of various devices to OPC network
This procedure creates availability of accessing all registers
in PLC program from any OPC client software. Now in
LabVIEW environment, the tagging of PLC registers with
particular blocks in LabVIEW is done through data binding
option in LabVIEW. The NI-OPC server has been successfully
implemented and monitoring is done using LabVIEW as
shown in figure 5.
As explained earlier experimental data has been taken
two times, one with 60% control valve opening and second
with 75% opening. Now the transfer function derived from
both readings. But after auto tuning both transfer function in
MATLAB, the obtained values of P, I, and D are entered in
the PLCs PID block and compare the results, it is found that
from first readings transfer function having better accuracy
than second readings. Here accuracy is means tracking of
process value nearer to the set point. So the Transfer function
is,
2.54
Transfer function T(s)= 55.32s+1
e−42.29s
VI. IMPLEMENTATION OF PID CONTROLLER
Fig. 5. Screen shot of LabVIEW front panel and block diagram panel for
heat exchanger process
V. MATHEMATICAL REPRESENTATION OF HEAT
EXCHANGER LOOP
We have first found the transfer function and put that in
MATLAB simulink script and obtained PID values by auto
tuning the feedback loop.
The PID instruction used in Allen Bradley 1200 PLC actuates
the hot water flow rate by sending an output signal in the
form of 4 to 20 mA to the control valve [10]. The PID
controller calculate the output value according to Controller
Gain (Kc), Reset time (Ti) and Rate time (Td) which is entered
by the operator. Depending on error value, the PLC controller
produces output which in turn causes the actuation of control
valve element. The PID controller is tuned in such a way
that we should get minimum steady state error, insensitivity
to load disturbances and an acceptable transient response to
set point changes and disturbances. The RS Logix software
provides PID instruction and its configurable parameters which
is illustrated in fig. 6.
VII. RESULTS AND DISCUSSION
Here transfer function of heat exchanger loop is found out
by mathematical modeling of process. The shell and tube
type heat exchanger system shown above is of single input
The readings comparisons analyzed by with PLC and
without PLC (Here without PLC means controlling of Heat
exchanger is done using PID controller connected to system
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Performance parameter indices
Rise time (tr in sec)
Peak time (tp)
Overshoot (%)
Settling time (ts in sec)
Process output (Feedback PID with Delay)
Real time controller signals
Simulation
Without PLC
With PLC
115
320
285
143
350
300
3.525
8
5.75
360
475
385
TABLE II
S HELL AND TUBE TYPE HEAT EXCHANGER PERFORMANCE PARAMETER
ANALYSIS
Fig. 6. Screen shot of PID block in Allen Bradley PLC
itself) and through MATLAB simulation and by determining
the performance parameters such as rise time, settling time,
overshoot (%) and peak time as shown in table 2. From the
obtained results, it is cleared that the system performance
parameters have been improved when it has PLC interconnection. This method provides accurate tracking of set point
stabilization.
Fig. 7.
card or NET-ENIW card, it provides Ethernet/IP connectivity
for Micrologix controllers. We have reduced the cost of this
module in our project by connecting PLC inputs and outputs to
Labview through NI-OPC server and by connecting Labview
to Internet, remote monitoring and controlling has been done
as shown in fig 8. Block diagram window is not shown here
for fig 8 because it is somewhat same like fig 5 only the
difference is that, here extra setting for web publishing tool
has been done.
We are controlling and monitoring the process in Labview
through internet and LAN so operator or client can easily
access the process remotely, thus the time for checking the process on field will reduced. In enhancement to this automation
we can also connect the process through android mobile. We
can send SMS (Short Messaging Service) when temperature
is above a certain range, by using GSM (Global system for
mobile) module.
Performance characteristics of feedback control system
Here it should be remember that, the data rate of PLC is
2.6 ms, so if PID block is implemented in PLC, the algorithm
definitely receives large number of signals per second. In
this way, it will produces more number of samples of output
signals to control valve which in turn results better settling
of the system [11]. As compared to all results, the process
with PLC-SCADA interconnections gives faster settling time
and rise time when compared to process with SCADA of heat
exchanger system itself (it means PID setup of process itself) is
as shown in fig 7. From the results we conclude that, the PLCSCADA interface provides the system to obtained somewhat
similar nature of result as simulated results which are done
using MATLAB.
VIII. ADVANTAGES AND BENEFITS
For connecting PLC to Local area network we require
special module provided by Allen Bradley which is NET-ENI
Fig. 8. Screen shot of LabVIEW after connecting to web
IX. C ONCLUSION
The performance of heat exchanger system has been experimented through various tools such as PLC, SCADA,
LabVIEW, and internet. The interconnection of AB Micrologix
PLC and NI-OPC (LabVIEW) server has significantly improved the performance parameter of cny conventional system.
Thus the process can connect to PLC-LabVIEW through OPC
network. Thus the process response using LabVIEW is better
than PLC. No doubt, PLC plays the main role and provides
the proper results with continuous excel format reports which
is useful to the operator and engineer to access the information
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of plants or any process. But when PLC connected with NIOPC server, the information can be amplified and processed
for further analysis. Also the PLC data can be completely
monitored and controlled through remote station by using web
publishing tool in LabVIEW is successfully experimented.
LabVIEW gives the flexibility to send SMS (Short Messaging
Service) by using GSM (Global system for mobile) module is
also experimented.
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