Analysis of generating costs have shown that approximately 70% of operating costs are for generating power and of this approximately 70% is for the cost of the coal. For these reasons P²EP has been designed so that Management at all levels are made aware of the areas in which its attention will obtain the largest commercial return.
The four main controllable factors which have the largest influence on this cost are:
- A Plant Efficiency
- B The Plant Thermal Losses
- C Plant Reliability
- D Plant Availability
Standard P²EP configuration addresses the first two, with the last two available as options if required…
P²EP calculations are based on British Standards. The main benefit of P²EP is that it measures the dynamic data measured on the plant against targets that are derived from acceptance tests and calculates the percentage deviation from target for the running conditions under current conditions as well as calculating the cost of the loss. This provides an indication of the area that requires action to reduce the loss and improve reliability as well help to keep the plant running optimally.
The targets in the program are derived from acceptance tests or guaranteed performance tests of the specific plant data targets are not fixed they change with load and are corrected back to design or acceptance test conditions, the corrections are calculated for the on load conditions so that the running sent out heat rate for the plant conditions can be calculated from the target heat consumption. A station target heat rate is calculated from the units target heat rates and compares the actual heat rate to derive the overall efficiency of the whole plant.
Click on diagram for more detailed information
P2EP calculates a loss between the actual and target as well as the incurred cost of the loss. An important feature of P2EP is that it allows a comparison of the overall station efficiency from both the Direct and Indirect sides. The Direct side comprises all the chemical energy burnt as fuel to produce heat in the boiler to convert water to steam i.e. coal and fuel oil. The Indirect side is all the actual data measured using field devices on the plant and from this the total accountable losses are derived between actual and target for the load and running conditions. In summary this can be represented as:
Direct P2EP factor (actual heat rate)