Method for monitoring process equipment and process equipment

Abstract

The invention relates to a method for monitoring a process plant (100), wherein a value (121) of at least one performance parameter (120, 220) of the process plant (100) is determined from actual values ​​(111) of at least one operating parameter (110, 210) of the process plant occurring during operation of the process plant (100) using a model (200) of the process plant (100), wherein a comparative value (221) of the at least one performance parameter (120, 220) of the process plant (100) is determined from set values ​​(100) of the at least one operating parameter (110, 210) using the model (200), and wherein at least one performance gap (230) of the operation of the process plant (100) is determined based on the mutually corresponding values ​​(121) and the comparative value (221) of the at least one performance parameter (120, 220), and a process plant (100).

Description

[0001] The present invention relates to a method for monitoring a process plant, such as an air separation plant, as well as a computing system for executing the method and a process plant. Background Art

[0002] Process equipment is generally understood to mean equipment that carries out material changes and / or transformations by means of targeted physical and / or chemical and / or biological and / or nuclear processes. These typically include comminution, screening, mixing, heat transfer, rectification, crystallization, drying, cooling, filling, and superimposed material transformations, such as chemical, biological, or nuclear reactions.

[0003] Air separation is a typical example of the separation of a feed fluid stream into its individual fluid components. The production of liquid or gaseous air products by cryogenic separation of air in a (cryogenic) air separation unit (ASU) is known and is described, for example, in a publication by H.-W. The book "Industrial Gas Processing" edited by IEEE Trans. Gas Processing Technology describes this in detail in Chapter 2.2.5 "Cryogenic Rectification".

[0004] Air separation plants have distillation column systems, which can be designed, for example, as two-column systems, in particular the typical Linde two-column system, but can also be three-column or multi-column systems. In addition to distillation columns for obtaining liquid and / or gaseous nitrogen and / or oxygen (e.g., liquid oxygen, LOX, gaseous oxygen, GOX, liquid nitrogen, LIN and / or gaseous nitrogen, GAN), i.e., distillation columns for nitrogen-oxygen separation, distillation columns for obtaining other air components, in particular the inert gases krypton, xenon, and / or argon, can also be provided. Distillation columns are also called distillation columns.

[0005] Such process plants are monitored in all cases during their operation, in particular the resulting power consumption or energy consumption being determined, so that it is possible to determine later, if appropriate, how much energy could have been saved.

[0006] Against this background, the object of the present invention is to improve the operation of a process plant, in particular with regard to its efficiency. Summary of the Invention

[0007] This object is achieved by a method for monitoring a process plant, a computing system for executing the method, and a process plant having the features of the present invention. Implementations are the subject of the technical solution of the present invention and the following description.

[0008] Advantages of the present invention

[0009] The present invention relates to a method for monitoring a process plant, such as that described in detail above, specifically using a process plant model.

[0010] Such a model of a process plant (digitally) maps the plant, in particular its operating state, and is implemented, for example, on a suitable computing system, such as a computer. Input values ​​can be fed into the model, and the model generates corresponding output values, specifically as it would (ideally) operate during the plant's own operation. This also means that various operating parameters of the plant, such as the flow of a medium in the process plant (in the case of an air separation plant, for example, air or air components such as oxygen or nitrogen), the temperature of a component of the process plant, and / or the temperature, composition, and / or pressure of a medium in the process plant, are mapped accordingly to the model. This can be done, for example, using suitable equations.

[0011] The output values ​​that the model then generates from the input values ​​corresponding to the operating parameters are, in particular, parameters that are indicators of the power or efficiency of the process plant (English: Key Performance Indicator). In the present invention, these parameters should be referred to as "performance parameters". In this case, they can be, for example, the power consumption or efficiency of a component of the process plant, the power consumption or efficiency of the (entire) process plant, and / or the recovery rate of a medium in the process plant (for example, argon in the case of an air separation plant).

[0012] In such a model, idealized predictions or values, i.e., setpoints, can be determined for one or more operating parameters of the system. With these setpoints, the system operates (as perfectly as possible) according to the specified values ​​or also based on empirical values. In other words, the system also has the (best possible) values ​​for the performance parameters. In this case, ambient conditions such as air temperature and cooling water inlet temperature, for example, are also taken into account when creating the model.

[0013] In the proposed method, a model of the process plant is used to determine the value of at least one performance parameter of the process plant from actual values ​​of at least one operating parameter of the process plant occurring during operation of the process plant. These actual values ​​can be measured, for example, or estimated, for example, by an observer.

[0014] Furthermore, the use model determines a comparative value for at least one performance parameter of the process plant from a setpoint value, i.e., the aforementioned idealized value or specified value, of at least one operating parameter. In other words, the use model determines the value of the performance parameter, on the one hand, from the idealized specified value of the operating parameter, and on the other hand, from the (currently) actually existing or used value of the operating parameter.

[0015] Based on the corresponding values ​​and comparative values ​​of at least one performance parameter, i.e., in particular value pairs each consisting of a value and a corresponding comparative value corresponding to the same operating state or the same point in time, at least one performance gap in the operation of the process plant is then determined. In the simplest case, the difference between the value and the comparative value can be determined for this purpose.

[0016] In this context, the term "performance gap," similar to the term "performance parameter," should be understood as the gap or difference between the actual value of, for example, power consumption and the theoretically or ideally achievable value. The same applies, for example, to the actual yield of recycled media and the theoretically or ideally achievable yield. Therefore, the performance gap determined in this way indicates a certain potential for savings or improvements in the operation of the process plant.

[0017] In this case, it is particularly advantageous to make the determined power gap or the determined power gaps (in the case of several performance parameters) available to the relevant positions or personnel or to all persons via a communication device in a suitable manner. This can be done, for example, via an (automatically sent) email or similar means, with the method preferably being implemented on a computer system. Similarly, it can also be displayed or presented on a suitable display device, for example in the control room of the process plant.

[0018] The value of the at least one performance parameter and the (associated) comparative value are advantageously determined at regular time intervals, for example every hour, or in predetermined operating states, and where appropriate also always after a change in the operating state of the process plant. This makes it possible to identify possible performance gaps or improvement potentials as soon as possible.

[0019] Preferably, the statistical relevance of at least one performance gap is determined based on a plurality of mutually corresponding values ​​and comparative values ​​(i.e., the aforementioned value pairs) of at least one performance parameter. This is particularly applicable when there are several performance parameters. This can also be referred to as a hypothesis test. In this case, the current mutually corresponding values ​​and comparative values, for example, from the last ten hours, are considered as a sample of mutually corresponding values ​​and comparative values ​​previously determined, for example, within a one-month period, and their statistical relevance is evaluated. It is also conceivable to use not only previously determined values ​​and comparative values ​​of the relevant device, but also values ​​and comparative values ​​of other similar devices.

[0020] In this case, for example, frequently occurring performance gaps can be rated as particularly important and then, for example, as performance gaps that need to be addressed first. This also applies to particularly high or large performance gaps. It is also conceivable to define a threshold value (e.g., an average value) for a specific performance parameter or to determine it from past values ​​or comparative values, and to only rate a current performance gap as important if this threshold value is exceeded.

[0021] It is also particularly preferred to determine improvement measures for the at least one performance gap and then, in particular, to make these improvement measures available to the relevant positions or personnel or to provide them to the relevant positions or personnel in a suitable manner, just like the performance gap itself. Such improvement measures may, for example, be changes in operating parameters. In this case, suitable measures may be determined, for example, based on empirical values ​​or test values, but it is also conceivable that such measures are determined based on the actual values ​​and set values ​​of the operating parameters. For example, it may be suggested to change the value of the operating parameter to the set value or at least to adjust it in this direction. However, it is also conceivable that the measures do not depend directly on the operating parameters or even on the operating parameters. Alternatively, a maintenance operation may be proposed, such as a cleaning process at the equipment (in the sense of improvement measures). It is also conceivable that improvement measures generally involve troubleshooting process equipment.

[0022] When assessing the importance of performance gaps and / or corresponding improvement measures, an analysis is expediently performed with respect to several operating states of the system.

[0023] In this context, a static significance indicator can be used, which allows for a simple implementation but ultimately results in the same assessment of the same performance gap or improvement measure. However, it is also possible to use a dynamic, i.e., variable, significance indicator, which allows for a detailed assessment of the importance of the performance gap or improvement measure, depending on the situation.

[0024] This makes it possible to carry out improvements with a high potential for improvement first, while less important improvements are delayed, for example.

[0025] In principle, the proposed method can be used for all types of process plants. However, it is particularly suitable and advantageous for process plants that process gases, such as air separation plants or CO2 plants, in particular CO2 liquefaction plants, because the improvement potential is particularly high in these plants. In CO2 liquefaction plants, a material stream that mainly or significantly contains CO2 is refined by removing impurities and liquefying the thus purified CO2.

[0026] A particular advantage of the proposed method and the use of a model of the process equipment is that the accuracy with which the model maps to the process equipment is relatively unimportant, since both the value and the comparative value of the at least one performance parameter are determined using the same model. Therefore, any deficiencies in the model have the same, or at least very similar, impact on both the value and the comparative value, while having little or no influence on the formation of discrepancies.

[0027] Furthermore, the present invention relates to a computing system (or computing unit) for monitoring a process plant, which is adapted, in particular in terms of programming technology, to carry out the method according to the present invention. Such a computing system can be provided, for example, as a separate device, but can also be integrated into a control and / or regulating system for such a plant.

[0028] Furthermore, the subject matter of the present invention is a process plant, in particular a process plant for processing gases, having a computing system according to the invention.

[0029] The invention is explained in more detail below with reference to the accompanying drawings, which show various plant parts, with the aid of which the measures according to the invention are explained. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The sequence of the method according to the invention is schematically shown in a preferred embodiment.

[0031] Figure 2 A diagrammatic representation of the performance gap in the method according to the invention using a preferred embodiment is shown.

[0032] Figure 3 A diagrammatic representation of the performance gap in the method according to the invention using a further preferred embodiment is shown. DETAILED DESCRIPTION

[0033] exist Figure 1 The flow of the method according to the invention in a preferred embodiment is schematically shown in FIG. For this purpose, a process plant 100 , such as an air separation plant, is roughly schematically shown.

[0034] To this end, an exemplary operating parameter 110 and a performance parameter 120 are shown, where the latter is affected by the former. As previously mentioned, the operating parameter may be, for example, a medium flow rate or temperature, while the performance parameter may be, for example, the power consumption of the process equipment or the recovery rate of the medium. It should be understood that in a typical process equipment, several different operating parameters and several different performance parameters exist.

[0035] Furthermore, a computing system 300, such as a computer, is shown on which the proposed method for monitoring the process equipment 100 can be executed. For this purpose, a model 200 of the process equipment 100 is used, for example, within the context of a suitable program, and is used to map the process equipment as closely as possible to reality. For this purpose, operating parameters 210 and performance parameters 220 are also provided, which correspond to the operating parameters 110 and the performance parameters 120, respectively.

[0036] It should be understood that those operating parameters or performance parameters that should be monitored are mapped in the model 200. The actual relationship between the operating parameters and the performance parameters can be represented in the model 200, for example, by suitable equations.

[0037] Here, model 200 is fed with input values, and it outputs corresponding output values, specifically as it would (ideally) be during the operation of system 100 itself. In this case, idealized predictions or values, i.e., setpoints, can be determined for operating parameters 110 or 210 (this applies to several operating parameters, respectively). With these setpoints, the system operates (as perfectly as possible) according to specified values ​​or based on empirical values, i.e., the system also has (as best possible) values ​​for the performance parameters. By way of example, such setpoints are denoted by 211.

[0038] In the proposed method, the actual, measured, or estimated value 111 of the operating parameter 110 or 210 is now used to determine the corresponding value 121 of the relevant performance parameter 120 or 220 using the model 200. Simultaneously or in parallel, a corresponding value, here referred to as comparison value 221, is also determined or calculated from the idealized value or setpoint 211 using the model 221. That is, the value of the performance parameter is determined using the model 200, on the one hand, from the idealized setpoint value of the operating parameter and, on the other hand, from the (currently) actually existing value of the operating parameter.

[0039] Based on the values ​​121 and comparison values ​​221 of the performance parameters 120 or 220, which correspond to one another, i.e., in particular, value pairs each consisting of a value and a corresponding comparison value corresponding to the same operating state or the same point in time, a performance gap 230 in the operation of the process plant 100 is then determined. In the simplest case, the difference between the value 121 and the comparison value 221 is formed for this purpose.

[0040] In this context, the term "performance gap," as previously described, should be understood to mean, for example, the gap or difference between the actual power consumption and the theoretically or ideally achievable power consumption. Thus, the performance gap 230 determined in this manner indicates a potential for savings or improvements in the operation of the process tool 100.

[0041] Based on the data accumulated over time regarding the performance gap, the statistical relevance of the performance gap 230 can now be determined for the current value of the performance gap, for example, within the context of a statistical analysis 240. Furthermore, additionally or alternatively, improvement measures 250 can be determined, which describe how the potential for more efficient operation of the process equipment 100 due to the discovered performance gap can be better exploited. Both the performance gap and the improvement measures can then be made available via a communication device 310. The communication device can be, for example, a (digital) display device or an email, which is then sent accordingly to the relevant personnel.

[0042] exist Figure 2 Schematically, a representation of the performance gap in the method according to the invention using a preferred embodiment is shown in FIG. For this purpose, a display device 400 with corresponding content is shown as an example of a communication device.

[0043] In this figure, four different performance parameters are listed sequentially in a column on the left, one of which is labeled 420. To the right of this column, performance gaps 430 or corresponding values ​​or amounts associated with these performance parameters are displayed in the form of bars and floating ranges. For example, one of the performance gaps is labeled 430, and the associated floating range is labeled 431. This display of performance gaps allows personnel to quickly and roughly understand where savings or efficiency improvements are feasible.

[0044] exist Figure 3 Schematically, a representation of the performance gap in the method according to the invention using another preferred embodiment is shown in FIG. For this purpose, an e-mail 500 with corresponding content is shown as an example of a communication means.

[0045] In this diagram, different performance gaps and the corresponding values ​​are shown in sequence on the left side, by way of example, with which the overall savings potential can be identified. By way of example, one of these performance gaps is labeled 530, and a legend is indicated by 535, with which the individual bars on the left can be assigned to performance parameters, for example.

[0046] In the upper right area, three different performance parameters are listed, one of which is labeled 520. To the right of these, improvement measures associated with these performance parameters, if any, determined through analysis, are displayed, one of which is labeled 550. This display of performance gaps and improvement measures allows the appropriate personnel to quickly and easily understand how savings and efficiency gains can be achieved particularly easily and quickly. It is also conceivable to interactively design the content of the exemplary display of the email.

[0047] Overall, the method proposed and explained based on the exemplary embodiments makes it possible to achieve a particularly simple, rapid and efficient improvement of the operation of a process plant, in particular by automatically displaying savings methods and proposing improvement measures.

Claims

1. A method for monitoring a process plant (100), wherein the method is performed by a computing system (300), wherein during operation of the process plant (100), the computing system (300) receives an actual value (111) of at least one operating parameter (110, 210) of the process plant, wherein a value (121) of at least one performance parameter (120, 220, 420, 520) of the process plant (100) is determined from the actual value (111) of the at least one operating parameter (110, 210) of the process plant occurring during operation of the process plant (100) using a model (200) of the process plant (100), the model (200) of the process plant (100) representing the operating state of the process plant, wherein a comparative value (221) of the at least one performance parameter (120, 220, 420, 520) of the process equipment (100) is determined from a set value (211) of the at least one operating parameter (110, 210) using the model (200), and At least one performance gap (230, 430, 530) in the operation of the process plant (100) is determined based on the mutually corresponding values ​​(121) and the comparison value (221) of the at least one performance parameter (120, 220, 420, 520).

2. The method according to claim 1, wherein the value (121) and the comparison value (221) of the at least one performance parameter (120, 220, 420, 520) are determined at regular time intervals and / or in a predetermined operating state of the process device (100).

3. The method according to claim 1 or 2, wherein the statistical relevance of the at least one performance gap (230, 430, 530) is determined based on a plurality of mutually corresponding values ​​(121) and comparison values ​​(221) of the at least one performance parameter (120, 220, 420, 520). The method according to claim 1 , wherein an improvement measure ( 250 , 550 ) is determined for the at least one performance gap ( 230 , 430 , 530 ). The method according to claim 4 , wherein the improvement measure ( 250 , 550 ) is determined based on a static significance indicator. The method according to claim 4 , wherein the improvement measure ( 250 , 550 ) is determined based on a dynamic significance indicator.

7. The method according to one of claims 1-2 and 4-6, wherein the at least one operating parameter (110, 210) is selected from the group consisting of a medium flow in the process equipment, a temperature of a component of the process equipment, a temperature of the medium in the process equipment, a pressure of the medium in the process equipment, and a composition of the medium in the process equipment.

8. The method according to one of claims 1-2 and 4-6, wherein the at least one performance parameter (120, 220, 420, 520) is selected from the group consisting of power consumption of a component of the process equipment, power consumption of the process equipment, recovery rate of a medium in the process equipment, effectiveness of a component of the process equipment, and effectiveness of the process equipment.

9. The method according to one of claims 4 to 6, wherein the at least one performance gap (230, 430, 530) and / or the at least one improvement measure (250, 550) is provided via a communication device (310, 400, 500).

10. The method according to claim 9, wherein an air separation plant or a carbon dioxide liquefaction plant is used as the process plant (100).

11. A computing system (300) for monitoring a process plant, the system being adapted to perform the method according to one of the preceding claims.

12. A process tool (100) having a computing system (300) according to claim 11.

13. The process equipment (100) according to claim 12, wherein the process equipment (100) is a process equipment for processing gases.

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