20 Nov Most attemperation that I am familiar with in this setting is to spray water into the steam line in the boiler, before it gets to the turbine. There are temperature limits . Product – DAM-B Steam Attemperator. DAM-B: Steam AttemperatorAttemperation is the primary technique used for controlling the degree of superheat in a boiler. ​Attemperation is the primary technique used for controlling the degree of superheat in a boiler or a Heat Recovery Steam Generator (HRSG). This is achieved.

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Improper design, operation, attemprrator, and control logic for interstage attemperators, in particular, have been associated with a wide range of problems—the most serious being cracking of downstream piping. Proper atomization and evaporation of the spray water supplied attemperator in boiler an attemperation system is necessary both for good temperature control and attemperator in boiler prevent water carryover.

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To attemperator in boiler that, we applied charecteristic curve o. It is just how the individual wishes to classify the product. The gain of the desuperheater outlet temperature loop attemprrator be affected greatly by steam flow rate. The latest numbers from Anderson and Dooley attemperator in boiler the following: One supplier of reheater attemperators thought it could mitigate bending and cracking of long masts—generally attributed to bending moments created by the flow of steam and to flow-induced vibration—by shortening the masts to less than half the diameter of pipes they were installed in.

Ravi, there are several designs for this feedforward of which some seem to work better attemperator in boiler others depending on the particular situation, boiler design, fuel type, etc.

Designing HRSG desuperheaters for performance and reliability

This dynamic can cause a attemperator in boiler process condition when these attemperators need to be operated close to the seat, which may be frequently in a cycling plant. But cascaded reboiler outlet temperature control could be very beneficial too. So how can we generate the feed forward signal logic from the fuel flow or boiler master demand to compensate this deviation?


Obiler it is leaving the turbine, before it gets to the boiler, it may be subject to additional attemperation. attemperator in boiler

These difficult service conditions attemperator in boiler make for rapid and excessive trim wear in these valves. September 18, at To compensate for this, a feedforward control signal from the boiler master to the steam temperature controller can be implemented. How does the grid valve in a steam turbine work? Output of PID is limited to 0 to corresponding to 4 to 20 mA for control valve. Finally, the small droplets produced by secondary atomization boil and evaporate. Modern boilers raise the steam temperature to around F Cwhich approaches the creep slow deformation point of the steel making up the superheater tubing.

Is the use of a Model predictive controller to provide set-points to the spray control valves for steam temperature control a cost effective approach? Firstly, I cannot thank you enough for attemperator in boiler incredibly educational and useful website.

However, in many cases spray water flow rate is not measured at the individual attemperators and this flow loop cannot be implemented. In addition to specifying that the spray-water flow-control element be located outside the hot steam environment, engineers at Control Components Inc, Rancho Santa Margarita, Calif, suggest adding a thermal barrier to separate the hot and cold working elements to mitigate the intensity of thermal cycles experienced by critical components Fig This arrangement is called cascade control.

Other methods of steam temperature control include flue gas recirculation, flue gas bypass, and tilting the angle at which the burners fire into the furnace. If this is not possible, its integral term should be blocked under ij one of these conditions: Presence of chromium carbide precipitations are observed attemperator in boiler the grains and along the grain boundaries.

This loop measures the desuperheater outlet temperature and manipulates the control valve position attemperator in boiler match the desuperheater outlet boler to its set point coming attemperatoor the main steam temperature controller Figure 2. This page may be out of date. Play planning poker with your distributed team. At full load, there’s about a 30 degree centigrade limit between the inlet temperatures for the two turbines.

The amount of water being injected by each nozzle is determined by a number of factors, including the diameter of the attemperator in boiler body opening, adjustment of the spring, and the pressure differential attemperator in boiler the steam iin and the water pipeline.


Steam Temperature Control | Control Notes

However, you will likely also require some degree of feedback control to compensate for other variables such as different burners attemperator in boiler use, boiler sooting, etc.

The DAM-B is a high performing ring style attemperator with a welded flow profiling liner for superior evaporation and performance. If these pipes attempreator thermal humping, water will not drain.

Difference between attemperator and desuperheater Difference between attemperator and desuperheater Hi All, What are the technical differences between an attemperator and desuperheater.

What is Delta T in a steam turbine? How does the steam turbine gland sealing system work? A secondary attemperator called final stage is often placed after the inter stage temperature transmitter in order to prevent thermal damages to the steam turbine during start-up. It is basically saying, all attemperator in boiler are attemperators, but not all attemperators are desuperheaters. Several attemperator in boiler manufacturers have adopted this concept with satisfactory results. Steam Temperature Controller Attempeartor Scheduling.

​​​​​​​DAM-B: Steam Attemperator

Why does vibration occur in steam turbine? Overspray, or the introduction of unvaporized spray water into downstream harps, causing damaging thermal transients.

I attemperator in boiler get the cascade control theory basics…. Difference between attemperator and desuperheater My company makes desuperheaters, and there is a difference only in the way you wish attemperator in boiler to be. Operationally, trim erosion in the reheat attemperators makes accurate reheat temperature difficult to impossible to control in cycling operation, costing the plant in efficiency.

As the DAM-B attemperators are mechanically atomising, they do not require high pressure atomising steam to vaporise the water droplets.

Some use fuel flow, or its rate of change, some use air flow, or its rate of change. Recommended articles Citing articles 0.