Turbine Efficiencies

Remove all leaks into the condenser and its pipework.

Short and sweet thanx. We are already in the process yes, what else?

What are possible ways of reducing exhaust temp online?

Reduce steam flow through the turbine.

Dear Mr. PWSlack,

You have mentioned "Reduce steam flow through the turbine."

If steam flow is reduced, the out put/power developed WILL BE REDUCED - depending upon the Reduction in steam flow, if intentionally done.

Pl. enlighten the philosophy behind your views.

DHAYANANDHAN.S

The original poster asked about reducing the pressure. Reducing the flow will reduce the pressure. Reducing the condenser temperature will reduce the pressure. Reducing the leaks will reduce the pressure. Reducing the encrustations of barnacles and other persistent biology within the condenser will reduce the pressure, and all these good things will be in the user manual for the equipment, which the Original Poster would do well to open, read and inwardly digest.

Philosophy doesn't really come into it; the transcendental and meaningful existence of the turbine and its condenser are of no significant concern right now, or at the very least, far less than the continued pervasive persistence of use of the Caps Lock key throughout a number of CR4 threads.

What does your turbine manufacturer

/turbine manufacturer's web-site

/turbine manufacturer's owners manual

/turbine manufacturer's service tech

/turbine manufacturer's turbine engineer

/your on-site maintenance and operating staff have to say?

the impact of both heat rate and condensate ... - CONCO Systems‎

• Large Steam System Condensers - Heat Exchanger - Engineers Edge

If you search this forum using 'turbine condenser', you will find prior discussion of this general problem. If you would like more specific responses, you need to give more specific information, such as what has been observed, the system specifics (air-cooled, water-cooled, temps, pressures), etc.

Obviously condenser cooling water temperature has to be reduced to increase vacuum and thereby the output of the turbine. You may use an NDCT for better cooling of cooling water. Is turbine output increased in winter?

Thanx Irshad, yes cooler ambient temperature reduces vacuum increasing megawatt generation. This is my current problem. Getting our current cooling water cooler to increase productivity. Reducing steam flow is viable yes although productivity is important. Explain this NDCT to me please?

What is the local wet-bulb temperature today?

No evaporative cooling tower can achieve cooling water temperatures lower than that figure.

Dear Mr.vnteand,

You should furnish more details such as Vaccuum, Ejector Capacity, Steam Conditions for the Ejector, Cooling Water Circulation Rate and its Temp., etc.

On the operational front, scaling effect in the condenser tube, and Temp. difference, etc.

The Vaccuum and Log Mean Temperature plays a vital Role in condensing the steam and Condensate Temp. will depend on Vaccuum - relating to the Saturation Temp. If Vaccuum is 0.1 bar absolute the Condensate Temp. should be 45.83 Deg.C. and your Temp.of 51 Deg.C indicates vaccuum is less and it is 0.13 bar absolute there by considerable power out put from the Turbine is lost.

DHAYANANDHAN.S

That involves opening the User Manual and actually reading it.

Don't go there...

_{Oh, and it's 'vacuum', not 'vaccuum', btw.}

Two vital pieces of paper would be of advantage:

• A set of steam tables.
• A psychrometric chart.

A way of interpreting them would go well, as well.

NDCT is natural draft cooling tower. IDCT is induced draft cooling tower.

1) eliminate sources of air ingress, and consider advanced diagnostics to map out the cooling performance of the tubes in situ and online. (temperature sensors are available for this, but I will not provide a commercial link). This can reveal pockets where air is not efficiently removed.

2) make sure you have done all you can to meet the design specifications of the surface condenser - i.e. - is the circulation rate correct? - are the tubes clean of any biological fouling / mineral scale? - is the steam flow and pressure as applied to the turbine inlet precisely the same as for design specifications? - read the manuals, and verify. - how many tubes are plugged in the surface condenser? - is the boiler really producing the correct steam pressure and superheat temperature? - are the steam extractions working properly?

As you can see there are other questions outside the surface condenser, but primarily focus on the surface condenser. That 51 C hotwell temperature is highly elevated. We have similar sized GE units that operate near 46 C at 76% maximum load on hot days, but are 3300' elevation, and also in a dry climate with relative humidity seldom above 45% on the hottest days. If you are operating near the wet-bulb temperature due to high relative humidity, you will not be able to reach optimum inlet temperature for design.