The Importance of a Power Plant Performance Test Procedure

Conducting a performance test is a great opportunity to get into the details about the performance of your power plant. Depending of the extension of your power plant performance analysis, there will be a set of preparations to ensure the accuracy of your test and to minimize its test uncertainty.

Time invested into developing  a strong procedure will save time and money to your project.

At first glance, the main requirement is to comply with the performance testing codes applicable for your project. However, we need to remember that the performance testing codes from standardization entities such as ASME, ISO, DIN, ASTM and others gives you a solid background of the general activities, procedures and instrumentation to use. But the details on how, when and activities to actually do at site should be covered in a  power plant performance test procedure.

What is a power plant performance test procedure?

A power plant test procedure is a document that close the gap between:

• The international accepted performance testing codes
• The technical requirements of the test
• The contractual specification of the performance test
• Actual site conditions

In order to apply the applicable testing codes to your power plant, a site-specific power plant performance test procedure needs to be developed to account for the specifics of your power plant.

For example, the test procedure should answer in a simple and clear manner the following:

– Where to install  the testing instrumentation?
– What are the boundary conditions of the test?
– What instrumentation will be used during the test?
– Where the fuel analysis will be conducted?
– How the results will be calculated?
– In the case of an acceptance performance test, it will describe the contractual performance guarantees and the reference conditions for these values.
– It will contain the formats to fill out during the test
– Among many other details.

While the performance testing codes contain a lot of detail, they can’t cover all the specifics at your plant for which you require engineering judgment and testing experience.

Save time and resources for your power plant performance test

Another reason to develop test procedure is to ensure that you power plant, the instrumentation, personnel and equipment needed for testing will be ready at time of the test.

We should remember that in accordance with ASME PTC 46 the following are the recommended test durations for each type of technology.

As you can see, the actual performance test last few hours and requires sometimes months of preparations.

Therefore to ensure that time, money and resources are not wasted, a test procedure gives you the indication as of what activities or parameters to take care the most.

Engage site personnel 

Finally, a site specific power plant performance test procedure, helps the plant, and the team to understand in simple equations what are the main parameters that affect the performance of the plant.

The procedure will be a document of reference for any question related to the performance of the plant.

As we said the performance testing codes provide a general guideline of the requirements to conduct a performance test in accordance with the international standards. As with all the activities of a power plant; a power plant performance test requires enough planning to be able to execute an accurate and impartial test.

Each power plant has a different configuration, operating objectives, personnel, instrumentation, fuel and equipment.

What my power plant performance test procedure should contain?

A power plant performance test procedure should contain the following:

Parameters to Evaluate

The procedure will specify the parameters to evaluate and under what conditions. For example, most of the times, a performance test is conducted at baseload to measure the power plant heat rate. The procedure will specify if this evaluation will be done with certain auxiliary equipment in operation or offline. The location for fuel and power measurements, the list of auxiliaries in operation, the cycle isolation and other specific conditions to ensure every time we conduct a test, we can compare the test results over time as the testing is conducted under the same conditions.

Instrumentation to Use

Depending on the type of performance test, we will need to meet certain level of test uncertainty. This uncertainty is driving mainly by the precision of the instrumentation used. In the test procedure, there should be a list of the parameters that will be measured and the type of instrumentation to measure each one of them.

Reference Conditions

The parameters to evaluate are subject to fluctuations depending on weather and operational conditions. The procedure will have a list of this conditions at which the measured results will be corrected. The power plant corrected results allow the team to compare the results in the operating basis.

Power Plant Stability

During the test, the parameters of interests can’t fluctuate beyond a certain limit to ensure we are conducting a test in compliance with the performance testing codes.

Calculations

The procedure will have a very detailed section in which to specify the method to calculate the power plant performance test results. One important factor to evaluate the results are the correction curves to use.

Correction Curves

As we mentioned before, the parameters to evaluate fluctuate with conditions beyond the control of the plant. For example, ambient temperature, barometric pressure, fuel analysis or grid frequency are parameters that affect the operation of the plant significantly. The correction curves allow the plant to “correct” the measured results back to the reference conditions, so we can calculate results that can be used to be compared over time.

Methods & Codes to Use

There are individual activities during a performance testing program that require to comply with the applicable codes. For example, the calculation of test uncertainty can follow the ASME PTC 19.1 code or the calibration of testing instrumentation could comply with NIST traceability standards or another regulation. In the performance test procedure there will be a list of the codes to use for individual activities.

Data Collection

During a test, the data collection should follow the performance test procedure. For each data source there should be a reference of the type of data collection to use and the frequency of the readings.

Site-Specific Formats

There will be specific formats to use depending on the site requirements. The procedure will contain these formats and the reason for each of them.

The site-specific performance test procedure will be reviewed by all the interested parties in the performance test results and after a series of revisions; this document will become the official document to follow for all the performance test activities.

The document will be very specific for the type of test you want to conduct and the particular situation at your power plant.