Hello,
I have read an interesting article about soot blower system as a way to reduce NOx and flue gas temperatures.
http://www.bmsint.com/power/technical.html

More and more old power plants install soot blower systems during modernization. Most soot blower systems are PLC based. They can be installed as a standalone system. I wonder if it would be difficult to interface this system with DCS, so operator can start and stop soot blowing sequence or be notified if sequence is started without introducing new computer in the control room.

What are your experiences?
Many soot blower manufacturers claim technical possibility to interface with any kind of DCS, but I wonder if that is really true.
Do you know of any examples of communications between mayor DCS systems (Ovation, T3000 or 800xA) and PLC based standalone soot blower systems?

Thanks

 

I work for the sootblower manufacturer who largely developed the field of Intelligent Sootblower Systems. The company in your link is our exclusive partner for specialized sensors used in our system.

To interface to a DCS system is a fairly straightforward process and we have done this many times with all sorts of DCS systems.

For more information please visit:

www.diamondpower.com

Thanks. If you have any other questions on this then feel free to ask.

 

Hello,

It is very simple and easy to operate,you can operate sootblowers from DCS on Auto as well as on Manual. Need to incorporate limit switch feed back(for initial position). MCC feed back (energise/deenergise contact) of every blower you can provide blower bypassing facility at DCS

regards
CPPguy

 

Thank you for your information. I'd like to know about some application example where soot blower system is controlled and operated from DCS (doesn't matter if the system is a separate PLC and communicate wit DCS via some communication protocols).

It wouldn't be practical to operate soot blower system from additional PC (auto or manual) in the control room. That would make things more complicated for plant operators.

I'm interested in examples where Emerson Ovation DCS is interfaced with some soot blower system.

Soot blower system is usually independent from DCS and all control is enclosed within the separate PLC. I have found many web sites from manufacturers of various soot blower systems and many claim an easy integration with DCS, but there is also lack of some case studies examples.

Best regards,
Mik

 

You have basically two options:

1. Interface via comms (ethernet, profibus etc.) to an existing PLC (or even via hard wired signals).

All the core logic resides in the PLC. On the DCS only a simple command and feedback interface needs to be programmed.

2. Build all of the required logic direct into the DCS and have a hardwired interface out to the blower motor starters.

There are hundreds of examples of each type on power plants from 50MW to 1300MW.

Either way it is not a difficult thing to achieve.

I would recommend a comms interface to a dedicated PLC. When you program the logic direct into the DCS you need to take account of a relatively slow response time and this could cause problems if not correctly addressed.

I think the lack of case studies is probably down to the fact that either of the above configurations are very common.

All new build power plants will have some sort of DCS control for the soot blowers.

 

I sometimes wonder if we get hung up on communication speeds, scan times, where to put things, complications, operators not understanding etc etc.

When I configure a control system for a boiler, if sootblower control is required, I simply include it within the same controller and add additional I/O cards to accommodate the extra I/O.

The system will have two types of blowers. Retractable and rotary. The retractable will have two limit switches, one at the beginning of the travel, one at the boiler end. That is two digital inputs. There will be a digital output to start the blower. During the commissioning period the blower travel time, both inwards and outwards is measured. This time becomes part of the travel logic as we do not want a blower stuck in the furnace.

The rotary will have a position switch that has two functions. One to count the revolutions, and that number is operator adjustable, and secondly to stop the blower with the poppet valve closed.

There is other logic for warming the sootblower pipework up, telling the drum level control that steam is being used (if the take off point is not after the steam flow meter), as well as feed forward to the steam temperature control if there is a superheater installed. The blowing sequence will be two fold. First against the gas flow. That is from the chimney back to the furnace, then from the furnace back to the chimney.

Sootblowing costs money. A recovery boiler for instance has continues blowing. A number of companies have attempted to provide programs that tell the blowers when to activate only when necessary. Measurex in the eighties tried using temperature differential. Bailey used a complicated algorithm that split the boiler into efficiency sections.

I see one of the correspondents quotes the Diamond Power site. That contains a good amount of information. Why not contact them, or Bergen or a couple of others, the names I forget. I would be happy to send you a flow sheet of the sequence.

Do not get bogged down with how to put hardware together. Any decent DCS/PLC will handle it with ease. If it was Infi 90 it would take me a day!!

 

Interfacing Emerson Ovation DCS with Sootblower system, is via Serial interface card, usually RS485 4-wire communication.

You have to define the inputs to DCS and outputs from DCS in a config file, and load it into the SLC card, via the Proprietary RLC software.

You can give command via the logic programmed in DCS, ans also receive inputs from the PLC used for controlling the sootblower system.

 

Thank you for your replies.

I know that any decent DCS/PLC can handle soot blowing algorithm with ease. However, I'm not sure about the case, when soot blowing system is separately delivered to existing plant. In such cases, implementing algorithms in DCS is not an option. Here, interface between these two systems is of particular interest. I'm mainly interested in Ovation case studies.

In the meantime I have contacted few manufacturers and waiting for response.

We'll see...

 

Hello,
I am a controls engineer at a sootblower company and we have developed many systems for many plants that communicate with several DCS's.

In particular, we have developed 10-20 systems in the last several years that interface with an Ovation DCS. Generally it is done thru ethernet (SLC driver in the ovation) or sometimes 232 (same driver).

It isn't a real big deal.

Ryan

 

I have few questions about ISb.

1. There are two different type of Sensors (Heat flux sensor, Gauge). Which one should be used for heat flux measurement or Which one has more advantage?

2.What are the parameters are considered to calculate the operation of Soorblower/

3.Send me if you have any ref doc to [email protected].

 

Hello,

I have worked siemens s5 system plc based but operation command from dcs we can start the sequence.

if blower having the problem you can receive the trouble alarm

dcs siemens telepharmxp (relay logic) through hardware to plc

dcs getting feedback also from plc through hardware to dcs