Competitions to compare professional skills of fossil power plant operators.
One way of the fossil power plant operator training is a competition to test the professional skills of the fossil power plant operation personnel. From the point of view of the professional skill improvements the best results have inside-power-plant competitions when different operator shifts of the same power plant engage in the competition with each other. In the case a hunger for not to be the last ones stimulates the operation personnel to actively rise the personal professional level while preparing to the competition.
Competitions of the more high level – inside a power utility, between a few power utilities, All-Russian competitions and international competitions – are mainly organized to enhance the power plant operator profession prestige.
In this section we are going to pay attention to those part of the professional skills competitions of fossil power plant operators that our simulators concern – practical skills of boiler and turbine operators.
At the competitions to test the professional skills of the fossil power plant boiler and turbine operators some simulators are to be used because it is impossible to compete at a real power equipment. One of the main requirements for the simulators that are used at the competitions is the advanced adequacy. It is because if such a simulator is not fully adequate then a craftsmanship of the simulator running tells not about the professional skills but about a fact that the operator was able to cope with the particular piece of a software. Of course it can’t be the goal of any professional skills competitions.
For a company that designed, developed and supplied a simulator that is used at such a competition, the competition itself is the moment of the truth. From our wide experience we know that the more the simulator adequate
- the more seriously the participants treat it
- the more the participants demand of the simulator
- the more they try to squeeze out of the simulator
In enables to find such simulator errors that nobody would pay attention to under other circumstances. For example. While preparing to a competition a participant directed our attention that at some moment without an obvious reason the power unit fluctuated 3 MW of loading (it is about 1% of the nominal loading for the power unit). Of course in a regular situation nobody would pay any attention to that but it was not a regular situation – it was the competition preparation. The reason of the problem was the following. In the simulator’s software there are some tables of steam and water thermodynamic properties. The tables are used for calculations. The tables contain thousands of points. It turns out that one of the entropy points had value 1.43 instead of 1.34. When the simulator began to use the point for calculations instead of the previous one it resulted in the power unit fluctuation with no reason. We checked that the error was in the original printed material we used for programming. The error is 30 years old.
Another example. During some years our model of HP heaters had no censures. In 2003 while preparing to the 2-nd international competition Cyberthon-2003, one team made the following. After the unit trip while making a safeguarding by using a steam from an external source (steam collector for power plant maintenance) the team maintained the pressure in the feed water tank at the 0.6 MPa level. When they began to make the unit start-up after the safeguarding they quite early started to put the HP-heaters into the operation. To do it they supplied the feed water flow with 165°Ñ (165°Ñ is the saturation temperature for 0.6 MPa pressure) through the HP-heaters. They opened the HP-heaters steam gate valves and opened drainage line to dump the HP-heater distillate to the condenser. The bleed steam to HPH-6 pressure at that time was less then 0.6 MPa so the bleed steam that come to HPH-6 hadn’t to condense in the HP-heater but it had to fly to condenser. So the steam area of the HP-heater had to be under some vacuum. That time the simulator failed to simulate it. So we were to essentially redesign the simulation algorithm for HP-heaters in order to the simulators be able to adequately simulate such operation modes. Thus thanks to the competitions the adequacy of the HP-heater models in our simulators was essentially improved.
We could continue with the examples. It is very important that the competitions stimulate the simulator improvements. The present simulators of the “Power plant simulators” company go very far from the simulator of the company that was used in 1998 at the first competitions of Centrenergo where teams from 17 power utilities participated. But we are sure that no one our competitor till now didn’t achieve the quality level our simulators had in 1998.
Till now the different simulators of the “Power plant simulators” company were used for different competitions for more then 10 times. A few hundreds of the most experienced operators from all over the Russia and from abroad participated in the competitions. At all the competitions participants executed very intricate exercises, including the unit start-up from the hot reserve or warm conditions (or start-up of a boiler and a turbine in the case a competition was conducted on a simulator of a power plant with a common steam line). A few times the exercise included the unit trip, safeguarding, a few hours of cooling down and then start-up from the conditions formed as a result of the cooling down. It means that the start-up conducted from the beforehand unknown thermal conditions. The initial thermal conditions for start-ups or the unit cooling down time were so selected that the start-up time to be from 2,5 till 4 hours – it was decided that for the professional skills competitions longer exercises are not suitable. While doing a power unit start-up at the simulators both boiler operator, turbine operator and head of the shift are working together. During a start-up each team executes thousands of control actions. At the competitions teams are not limited with the power unit operational instruction only. Generally speaking they are allowed to do whatever then want to do, but the simulator has to correctly evaluate what was done. So for unit start-up from the same thermal conditions different teams could use different technologies. For example, at the 2-nd international competitions Cyberthon-2003 a 200 MW oil fired drum boiler unit with intermediate steam reheating was used. The power unit operation instruction requires to push the turbine through the HP-cylinder. At the same time the turbine operational instruction from the producer factory allows to push the turbine through the MP-cylinder. The turbine’s oil regulating system allows the push through the MP-cylinder too. At the Cyberthon-2003 5 teams performed the turbine push through the HP-cylinder while 1 team performed the turbine push through the MP-cylinder. It is obvious that the power unit start-up with turbine push from HP-cylinder considerable differs from the start-up of the same power unit with the turbine push from MP-cylinder. The simulator successfully cope with both start-up technologies.
There is a problem how to judge competitions to test the professional skills of the fossil power plant operation personnel. Till the 1998 all the judgments were done manually and controversies of all kinds appeared. Initially to reduce the human factor while the competition judgments, in cooperation with some experienced technologists a judging system to estimate quality of a power unit running in the frame of a simulator was developed and implemented as the simulator subsystem. Later on the judging system turned out to be very effective for the personnel training too. The judging system assigns valuations for the way the power unit was running.
The overall assessment consists of 2 parts:
- fail-safety evaluation of the power unit running
- economic evaluation of the power unit running
The fail-safety part of the overall assessment includes penalties for such operator actions like:
- switch-on a pump while discharge manifold of the pump has a too low pressure
- too fast heating or cooling of turbine’s stator metal or a metal of pipe-lines
- an ejector is working without a cooling
- too fast heating/cooling of built-in separator
- exceeding of allowable temperatures of metals of platen surfaces
The economic evaluation of the overall assessment includes the following factors that are being estimated for all the time of the exercise:
- total fuel consumption
- total condensate dump out of the thermodynamic cycle
- total sent-out electricity
- total steam consumption for power plant maintenance taken from an external source
- external electricity consumption for power plant maintenance
In essence the both parts reflect a money equivalent of the quality of the power unit running. If you often switch-on a pump with an “empty discharge manifold” then soon you is to spend money on its repair. And so on. The economic evaluation has an obvious concern with the money.
So the judging system stimulates the operator to produce more income taking into consideration both the short-term consequences and the long-term ones.
The numerous competitions conducted on our simulators with the using of the judging system obviously proved that even for the most experienced operators the economic constituent in essence is the higher mathematics – people that have been working on power plants for decades often don’t fully understand the economic basics of the fossil power units operations.
The 3-rd international competition to test the professional skills of the fossil power plant operators Cyberthon-2004 is going to be organized in October of 2004 in Johannesburg, South Africa. The organizer is the one of the first-rate power-generation company in the world – Eskom. The Eskom pays a great attention to the operator training. It should be mentioned that at present all the Eskom’s power plants have a simulator supplied by one of a well-known European or American companies. Some of the simulators are the full-scale simulators (with a real control room replica) while other ones are so-called the analytical ones (run on a set of a few computers only). The Cyberthon-2004 organizers could at discretion select a simulator to compete on. The Eskom from 1997 has been organizing own internal competitions on the base of available simulators. Nothing could prevent the Eskom to offer for the Cyberthon-2004 one of the own analytical simulators. A special meeting of the organization committee devoted to the simulator choosing was organized. We are sure that no one simulator vendor would require a payment to allow the using an own simulator for an international competition because it is the best possible advertising for any simulator – so no doubts that the financial questions couldn’t be a matter. However the Eskom’s management did choose a simulator from the “Power plant simulators” company. From our point of view it is an acknowledgement that the Eskom’s simulators developed by the leading world vendors, at least the analytical ones, have lower quality compare with the simulators developed by the Russian “Power plant simulators” company.