Ratanapala

23 Mar 2016

Recently there has been a spate of Island-wide power failures in Sri Lanka  and the Norochchalai Coal Power Plant has become the scapegoat every time and by inference the Rajapakse Administration.

By listening and reading about these incidents it has become clear that the precursors of the recent power failures are the outcome of exploding transformers. These incidents have become so highly politicized that the President of Sri Lanka and Commander in Chief of the Armed Forces – has deployed his forces to give security and protection to the power grid transformers on suspicion that the explosions are the results of sabotage.  No wonder Fools rush in where angels fear to tread”. This shows how quickly negligence” on the part of the authorities is white washed in preference for political mileage. A gullible and ignorant nation keeps on parroting Norchchalai Norochchlai for all their power ills!

It is most probable that the explosions and resulting damages to the transformers are due to large-scale current transients arising from sudden disruptions to the power distribution systems and the failure of system protection equipment to adequately manage the power grid integrity.

On the part of the Norochchalai Power Plant it is now becoming clear that it has automatically gone into a protective mode by shutting itself from the main power grid. The main boilers of the power plant have shed steam to relieve pressure in the boilers  to cool down in a prearranged sequence of automatic operations.  It also transpires that the power plant has no uninterrupted power supply system to manage the boiler auxiliaries – mainly pumps  and accessories during an unplanned  stoppage. Normally boiler auxiliaries which may take up to 10% of the generating capacity, run off the self-power generated but in the case of eventualities such as what happened in last few weeks in Sri Lanka,  a large power plant such as Norochachalai should have its own uninterrupted power supply (UPS), normally standalone diesel power generators which kicks in, moment the normal power supply to the Boilers are disrupted.

As for the transformers, a sudden surge of electricity in the form of current transients due to a sudden disruption to electricity supply can cause a transformer explosion. This is similar to Pipe Hammer” one get when a water valve is suddenly closed where extremely high pressure transients can sometimes cause catastrophic failures in water systems. As transformers detect an energy spike, they’re programmed to turn off, but it can take up to milliseconds for the shutdown. However fast those milliseconds may seem, they still may be too slow to stop the electrical overload. A chamber full of gallons of mineral oil keeps the circuits cool, but given too much electricity, the circuits fry and melt, failing and setting the mineral oil aflame. Mineral oil, in turn, combusts explosively  and catastrophically destroying  the transformer and nearby installations. All it takes is a trigger, a weakened component   and the circuits surge will get ahead of the safety breaker. Inadequate maintenance of transformer cooling oil (which by the way is highly carcinogenic) not renewed timely, whose  properties change with time and simply age could lead to insufficient heat transfer and transformer failure during an overload.

Many power failures are reported from the Norochchalai Power Plant since its installation a few years back. This being a Coal Powered Power Plant, over 80% of its equipments are mechanical. This is an area where mechanical engineering expertise is required and Mechanical Engineers with valid practical experience should be in charge.  Coal Powered Power Stations are very cumbersome installations comprising many mechanical components which require careful upkeep and maintenance –  compared to oil or gas fired installations. The main electrical component of the power plant is downstream of the Steam Turbines, in the Generators, the transformers, in the switchgear  and in the distribution system to the power grid.  The running and maintenance of Coal Power Steam Generation should not be in the hands of amateurs. Mere academic qualifications do not make one qualified to run a High Pressure Boiler installations. The Know How” of running and maintaining comes only from properly certified technical personnel with years of hands on” experience.  This is no place to get on the job” experience!)

From what I have read and heard so far the engineers in the CEB have not carried out of either HAZIDs (The Hazard Identification Study  is a process that breaks a project down into component parts for detailed analysis. This analysis helps identify hazards that could cause injury to personnel, asset damage or loss, environmental damage, loss of production, etc.) or HAZOPs (A hazard and operability study (HAZOP)  a structured and systematic examination of a planned or existing process or operation in order to identify and evaluate problems that may represent risks to personnel or equipment, or prevent efficient operation; it is carried out by a suitably experienced multi-disciplinary team (HAZOP team) during a set of meetings. HAZOP is a more detailed review technique than HAZID. It is also evident that CEB are not in possession of suitable simulation computer software for power grid analysis.

This type of power installation is usually used for base load applications only, due to the reason they take time to bring on line” and take off line”. Once charged, fired and in operation the installation should run non stop for long periods of time running into several months. Every time a high pressure boiler is shut down and started it runs through a thermal / mechanical stress cycle. Two many such cycles will prematurely age and weaken the installation leading to mechanical / thermal fatigue of boiler, refractories, the boiler tubes including premature corrosion, and deterioration of other susceptible materials and equipment and eventually catastrophic failure leading to disaster and costly repairs.

I was listening to the latest Aluth Parlimentuwa the other day. It transpired that an earlier offer from Japan for the supply and delivery of a state of the art Coal Powered Power Plant for Norochchalai had to be rejected due to bogus environmental concerns raised by the Catholic Church and Christian Church inspired NGOs. (This is the way the  Catholic Church is  piss marking” Kalpitiya / Putlam as part of the future Kristu Rajaya which they are pursuing in case Eelam becomes a reality and Sri Lanka balkanized!)

In many parts of the world Coal Power Plants are installed and run in close proximity to populations centers. Cleaning up of the effluents and off gas is no brainer with the currently available technologies.

Huntley Coal Power Station – situated in close proximity to  Huntley City, New Zealand

The current Coal Powered Power Plant had to be purchased from China as they were the only supplier available that could advance the necessary funding. It is necessary to understand the power plant received may well be one that has been tailor made for use in the Chinese Power Grid. Use of such a plant to supply nearly 50% of our power needs in Sri Lanka and its integration into the National Grid should have been well thought out by those versed in their respective professions.

Taking cheap shots at the Chinese, the  power plant itself and the  Rajapakse Administration that finally managed to set up the long overdue power plant in Norochchalai against  opposition from the Catholic Church and armchair environmental pundits  should stop. This is what made it possible for Sri Lanka to be the only South Asian country to deliver uninterrupted electricity supplies 24/7 to users who are now nearing 100% of the population.

The mud slinging campaign does not augur well for the engineers, technicians and professionals in Sri Lanka. It is worse when opinions are expressed by politicians who are near illiterates in technical matters and ignorant of what they are talking about. Born Again Christian Sajith Premadasa is proving to be one such looser!