Method for operating a gas turbine system, gas turbine system, computer program product and computer-readable medium

Abstract

The invention relates to a method, in particular a computer-supported method, for operating a gas turbine system, the method comprising the following steps: - detecting the nitrogen oxide emissions of the gas turbine system over a respective observation period; - determining the average nitrogen oxide emissions over a plurality of successive observation periods; - comparing the average nitrogen oxide emissions with an emission limit value; - adapting operating parameters in order to reduce the nitrogen oxide emissions if the average nitrogen oxide emissions exceed the emission limit value.

Description

[0001] 2024PF00298 Foreign version 1

[0002] Description

[0003] Method for operating a gas turbine plant, gas turbine plant, computer program product and computer-readable medium

[0004] The present invention relates to a method, in particular a computer-aided method, for operating a gas turbine plant. The invention further relates to a gas turbine plant, a computer program product, and a computer-readable medium.

[0005] Gas turbines play a crucial role in the energy transition. Their flexibility allows them to respond quickly to fluctuations in electricity demand.

[0006] When operating a gas turbine plant, certain emission limits must be observed. These may be stipulated by laws, regulations, directives, or similar provisions, or they may result from emissions trading. In particular, limits for nitrogen oxide emissions must be met. SCR catalysts are frequently used to reduce nitrogen oxide emissions. These catalysts undergo selective catalytic reduction, which reduces the nitrogen oxides in the turbine's exhaust gas. The selective catalytic reaction largely suppresses undesirable reactions. In practice, ammonia is used for selective catalytic reduction and is added to the exhaust gas. 2024PF00298 Foreign Version 2

[0007] The situation is problematic during the start-up of a gas turbine plant. The officially defined operating state, from which the plant must operate in compliance with emissions standards, may occur before the SCR catalyst has reached stable, controlled operation. This can lead to high emission levels for a limited period, exceeding the permitted annual or daily average emission limits, which are then factored into the calculation of these limits. Especially for plants that perform many starts per year, and where there is a significant difference between the emission levels during start-up and the emission limit, the start-up phase can have a considerable impact on emissions over the entire assessment period.

[0008] In addition, the limits for nitrogen oxide emissions are decreasing. This increases the difference between nitrogen oxide emissions during start-up, when the catalytic converter is not in stable, controlled operation, and the permissible limits for nitrogen oxide emissions during operation. The number of start-up cycles is also increasing, as gas turbines have to compensate for fluctuations in electricity supply, which are becoming more frequent due to the growing importance of renewable energies.

[0009] Against this background, the object of the present invention is to provide an alternative method for operating a gas turbine plant, which in particular can reduce nitrogen oxide emissions and / or the amount of auxiliary substances used, for example ammonia. 2024PF00298 Foreign version 3

[0010] This problem is solved by a method, in particular a computer-aided method, for operating a gas turbine plant, in particular a combined cycle turbine plant, which comprises the following steps:

[0011] - Recording the nitrogen oxide emissions of the gas turbine plant over a specific observation period;

[0012] - Determining the average nitrogen oxide emissions over several consecutive observation periods;

[0013] - Comparing average nitrogen oxide emissions with an emission limit value;

[0014] - Adjusting operating parameters to reduce nitrogen oxide emissions when average nitrogen oxide emissions exceed the emission limit.

[0015] The invention is based on the fundamental idea of ​​determining an average value of nitrogen oxide emissions over a longer period, recorded over successive observation periods, and comparing this average with an emission limit value, which in particular relates to a longer period. If it turns out that this emission limit value is exceeded by the average emissions of the respective observation periods under consideration, operating parameters can be adjusted to reduce nitrogen oxide emissions. Preferably, the operating parameters are then adjusted accordingly for the next observation period or several subsequent observation periods, in particular until the average nitrogen oxide emissions fall below the emission limit value again over this period.This allows for continuous monitoring of nitrogen oxide emissions and the implementation of appropriate measures if a limit value is exceeded. 2024PF00298 Foreign version 4.

[0016] Adjusting one or more operating parameters may depend on the size of the difference between average nitrogen oxide emissions and the emission limit value, and on the number of observation periods considered.

[0017] Preferably, the nitrogen oxide emissions include emissions of NO and / or NO2.

[0018] The observation period can be one week, several days, 24 hours, 12 hours, 6 hours, 3 hours, 1 hour, or 0.5 hours. Particularly preferably, the observation period is one hour. In this case, nitrogen oxide emissions are considered over one hour, and the average nitrogen oxide emissions are calculated over several consecutive hours.

[0019] In a further development, the emission limit value can refer to a reference period. In particular, the emission limit value can correspond to the permissible nitrogen oxide emissions over the reference period. The reference periods can be sub-periods of the reference period. In other words, the emission limit value can correspond to or reflect the maximum permissible nitrogen oxide emissions over the reference period. The emission limit value can be determined by dividing the permissible nitrogen oxide emissions over the reference period by the number of reference periods that fall within the reference period. If the reference period is one day, for example, the nitrogen oxide emissions can be divided by the number of days that make up the reference period. In a specific implementation, the reference period can be one year, in particular a calendar year.The assessment period (2024PF00298 Foreign Version 5) can be a fixed period or a rolling period. This means that the assessment period is either a fixed period, for example a calendar year, or it shifts continuously, for example the preceding year.

[0020] If the reference period is a fixed period, such as the calendar year, then the observation periods used to calculate average nitrogen oxide emissions can be any previous observation periods within the reference period. In other words, the entire previous portion of the reference period can be considered for calculating average nitrogen oxide emissions.

[0021] If the observation period is a single day, the current calendar year can be used as the reference period. In this case, the average nitrogen oxide emissions can be determined for all observation periods within the reference period. This means that, for example, the average nitrogen oxide emissions for the current calendar year are determined for each day. The daily average annual nitrogen oxide emissions can then be taken into account.

[0022] In a further embodiment, the gas turbine plant can include an SCR catalyst. An auxiliary substance, in particular ammonia, can be added to this catalyst. The addition of ammonia (NH3) and its mixing with exhaust gas can trigger a reaction that produces water and nitrogen. 2024PF00298 Foreign version 6

[0023] One operating parameter that can be adjusted to control nitrogen oxide emissions is the amount of additive supplied. This design is based on the consideration that the amount of additive, for example ammonia, supplied to the SCR catalyst influences nitrogen oxide emissions. Preferably, the amount of additive is increased when average emissions exceed the emission limit. This allows the additive supply, particularly of ammonia, to be precisely controlled, ensuring that ammonia consumption is kept as low as possible while simultaneously guaranteeing that nitrogen oxide emissions do not exceed the emission limit.In other words, the procedure can lead to the ammonia supply being adjusted in such a way that, if the emission limit is exceeded, emissions are reduced for the following observation periods or the next observation period, in particular until the average nitrogen oxide emissions are again below the emission limit.

[0024] The problem underlying the invention is further solved by a gas turbine plant with means adapted to perform the steps of the method as described above. Specifically, the gas turbine plant can include an SCR catalyst, wherein the SCR catalyst in particular comprises means for supplying an auxiliary substance, preferably ammonia. These may include means for controlling the amount of auxiliary substance.

[0025] In a further embodiment, the gas turbine plant can include a control device for carrying out the previously described method. In other words, the means for carrying out the method according to the invention can include a control device. 2024PF00298 Foreign version 7

[0026] Furthermore, the gas turbine plant may have measuring equipment for recording nitrogen oxide emissions.

[0027] The gas turbine plant can be designed as a combined cycle power plant (CCPP). In other words, the gas turbine plant can be a combined cycle gas turbine (CCGT). Such a plant is based on the idea that the hot exhaust gas stream from a gas turbine can be used to generate steam. The generated steam can then drive a steam turbine, for example, with different pressure stages. Preferably, the gas turbine and the steam turbine simultaneously drive a generator via a common shaft.

[0028] The problem underlying the invention is further solved by a computer program product comprising commands that cause the gas turbine plant according to the invention to carry out the process as described above.

[0029] Furthermore, the invention creates a computer-readable medium on which the computer program product is stored as described above.

[0030] For further details of the invention, reference is made to the dependent claims and to the description of an exemplary embodiment with reference to the accompanying drawing. The drawing shows:

[0031] Figure 1 shows the method according to the invention in a schematic representation.

[0032] Figure 1 schematically shows a method for operating a gas turbine plant, which is designed as a combined cycle gas turbine (CCGT) plant and contains an SCR catalyst. Ammonia can be supplied to the SCR catalyst as an auxiliary substance to reduce nitrogen oxide emissions.

[0033] The method according to the invention comprises several steps.

[0034] In step 1, the nitrogen oxide emissions from the gas turbine plant are recorded over a specific observation period. This can be done using appropriate measuring instruments that, for example, measure the composition of the exhaust gas leaving the SCR catalyst. In this case, the observation period is one hour. In other words, in step 1, the nitrogen oxide emissions are determined for each hour.

[0035] In step 2, the average nitrogen oxide emissions are determined over several consecutive observation periods. This means that the average nitrogen oxide emissions for one hour are calculated from the nitrogen oxide emissions of several consecutive hours, specifically all hours of the current calendar year.

[0036] In step 3, the average nitrogen oxide emissions are then compared with an emission limit value, and the difference is determined. This preferably refers to a fixed reference period of one calendar year, whereby the limit value is calculated by dividing the maximum permissible nitrogen oxide emissions over one calendar year by the number of reference periods in the year.

[0037] In step 4, the operating parameter is set to the

[0038] The amount of ammonia supplied to the SCR catalyst is adjusted if the average nitrogen oxide emissions exceed the emission limit value, in particular taking into account the magnitude of the difference between the average emissions and the emission limit value, as well as the number of observation periods.

[0039] This ensures that nitrogen oxide emissions do not permanently exceed the annual average. Instead, emissions are reduced if an exceedance of this limit is detected. This gives the operator of the gas turbine plant the assurance that the annual limit will be met at all times of the year, regardless of how the plant is operated for the remainder of the year.

[0040] Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples and other variations can be derived by the person skilled in the art without leaving the scope of protection of the invention.

[0041] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

Claims

2024PF00298 Foreign version 10 Patent claims 1. Method for operating a gas turbine plant, comprising the following steps: - Recording the nitrogen oxide emissions of the gas turbine plant over a specific observation period; - Determining the average nitrogen oxide emissions over several consecutive observation periods of a calendar year as the reference period, taking into account the daily average annual value of nitrogen oxide emissions; - Comparing average nitrogen oxide emissions with an emission limit value; - Adjusting the ammonia feed to an SCR catalyst of the gas turbine plant to reduce nitrogen oxide emissions for subsequent observation periods if the average nitrogen oxide emissions exceed the emission limit, the extent of the adjustment depending on the difference between the average nitrogen oxide emissions and the emission limit as well as the number of observation periods considered.

2. The method according to claim 1, characterized in that the nitrogen oxide emissions comprise the emissions of NO and / or NO2.

3. Method according to claim 1 or claim 2, characterized in that the observation period is one week, several days, 24 hours, 12 hours, 6 hours, 3 hours or one hour or half an hour. 2024PF00298 Foreign version 11 4. Method according to one of the preceding claims, characterized in that the emission limit value relates to a design period, in particular corresponds to or reflects the permissible nitrogen oxide emissions over the design period, and the observation periods form sub-periods of the assessment period.

5. Method according to one of the preceding claims, characterized in that the gas turbine system includes an SCR catalyst.

6. Method according to claim 5, characterized in that an auxiliary substance, in particular ammonia, is supplied to the SCR catalyst.

7. Method according to claim 6, characterized in that an operating parameter which can be adjusted to control nitrogen oxide emissions is the amount of auxiliary material supplied.

8. Method according to claim 7, characterized in that the amount of auxiliary material is increased when the average emissions exceed the emission limit value.

9. Gas turbine plant comprising means adapted to perform the steps of the method according to any of the preceding claims.

10. Gas turbine plant according to claim 9, characterized in that it contains an SCR catalyst, wherein the SCR catalyst in particular comprises means for supplying an auxiliary substance, preferably ammonia, wherein 2024PF00298 Foreign version 12 these means to control the quantity of auxiliary material include .

11. Gas turbine plant according to claim 9 or 10, characterized in that it includes a control device for carrying out the method according to any one of claims 1 to 10, and / or that it has measuring means for detecting nitrogen oxide emissions.

12. Computer program product comprising instructions that cause the gas turbine plant according to any one of claims 9 to 11 to carry out the method according to any one of claims 1 to 8.

13. Computer-readable medium on which the computer program product according to claim 12 is stored.

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