Open-loop and closed-loop control system of a deoxygenation plant

Abstract

The invention relates to a control and regulating system of an oxygen-reducing system, comprising at least one inert gas generator (30a, 30b), at least one oxygen concentration sensor (31a, 40), at least one actuator (32, 33, 41) for releasing inert gas, wherein the control and regulating system comprises a plurality of signal-connected controller modules (22, 24), each configured or configurable so as to enable the execution of one or more regulating functions, wherein the regulating functions are decentrally distributed to at least two signal-connected controller modules (22, 24).

Claims

1. An oxygen-reducing system configured to lower and maintain an oxygen concentration level in an enclosed protected area, comprising: an inert gas generator configured to generate inert gas; an oxygen concentration sensor; an actuator of the inert gas generator configured to release the generated inert gas; a plurality of signal-connected controller modules configured to execute one or more regulating functions, wherein the regulating functions are distributed to at least two of the plurality of signal-connected controller modules; an area controller of the plurality of signal-connected controller modules configured to use the oxygen concentration sensor for one or more of monitoring the oxygen concentration level in an enclosed monitored area or regulating the oxygen concentration level in the enclosed protected area by releasing the inert gas; and a master controller of the plurality of signal-connected controller modules configured to one or more of coordinate communication between components of the oxygen-reducing system or coordinate communication to points external to the oxygen-reducing system, wherein the plurality of signal-connected controller modules are dynamically configurable during operation, and wherein a first controller module is configured to assume execution of one or more regulating functions of a second controller module or vice versa.

2. The oxygen-reducing system of claim 1, wherein the plurality of signal-connected controller modules are modularly combinable with one another, and wherein each signal-connected controller module is differently configured by appropriate user inputs via an input interface.

3. The oxygen-reducing system of claim 1, wherein at least one of the plurality of signal-connected controller modules is further configured to execute regulating functions comprising: one or more of, (i) regulating the generated inert gas by switching on and off the inert gas generator; (ii) evaluating a sensor signal of one or more of the oxygen concentration sensor, a gas sensor, a temperature sensor, a volumetric flow sensor or a pressure sensor assigned to the inert gas generator, (iii) or activating the actuator of the inert gas generator.

4. The oxygen-reducing system of claim 1, wherein at least one of the plurality of signal-connected controller modules is further configured to execute regulating functions comprising: evaluating sensor signals selected from one or more of the oxygen concentration sensor, a gas sensor, a temperature sensor, a volumetric flow sensor, or a pressure sensor arranged in one of the enclosed monitored area or the enclosed protected area.

5. The oxygen-reducing system of claim 1, wherein at least one of the plurality of signal-connected controller module is further configured to execute regulating functions comprising evaluating signals from door contacts arranged in one or more of the enclosed monitored area or the enclosed protected area.

6. The oxygen-reducing system of claim 1, wherein at least one of the plurality of signal-connected controller module is further configured to execute regulating functions selected from one or more of: requisitioning an amount of the inert gas from the inert gas generator; activating a plurality of actuators in one or more of the enclosed monitored area or the enclosed protected area; activating displays configured to display oxygen concentration measurement values in one or more of the enclosed monitored area or the enclosed protected area; or activating, in case of alarm, one or more of an acoustic alarm or a visual alarm.

7. The oxygen-reducing system of claim 1, wherein the master controller is further configured to one or more of coordinate communication between components of the oxygen-reducing system or coordinate communication to points external to the oxygen-reducing system, by one or more of, distributing demands for inert gas quantities to a plurality of inert gas generators according to predefined criteria; distributing the generated inert gas to the enclosed protected area according to the predefined criteria; collecting and evaluating one or more of a status, a failure or an alarm message of at least one of the plurality of signal-connected controller modules; generating one or more of the status, the failure or the alarm message for one or more of display on a control panel or forwarding to an external continually manned location; activating displays to display sensor measurement values; and providing remote access to the oxygen-reducing system.

8. The oxygen-reducing system of claim 1, wherein at least two of the plurality of signal-connected modules have an identical range of functions and are signal-connected to one another so as to form an inherently redundant controller group.

9. The oxygen-reducing system of claim 8, wherein the at least two of the plurality of signal-connected modules of the redundant controller group are each configured to automatically take over one or more functions of each other signal-controller when a respective other signal-connected controller module experiences one or more of failure or overload.

10. The oxygen-reducing system of claim 8, wherein the plurality of signal-connected controller modules and redundant controller groups are arranged at a spatial separation from one another.

11. The oxygen-reducing system of claim 1, wherein the plurality of signal-connected controller modules are one of signal-connected or signal-connectable to a data storage and evaluation unit so as to enable long-term storage and evaluation of system data including one or more of control parameters, sensor data, environmental data, energy consumption data, failure or alarm messages.

12. The oxygen-reducing system of claim 1, wherein the plurality of signal-connected controller modules each have a peripheral recognition function to automatically recognize a type and mode of operation of one or more of oxygen concentration sensors, actuators, or other sensors connected to a respective signal-connected controller module.

13. The oxygen-reducing system of claim 1, wherein the plurality of signal-connected controller modules are self-configuring so that the regulating functions are automatically activated based on one or more of (i) a type and mode of operation of connected devices or (ii) input/output interfaces, the devices selected from one or more connected oxygen concentration sensors or actuators.

14. An oxygen-reducing system configured to lower and maintain an oxygen concentration level in an enclosed protected area, comprising: an inert gas generator configured to generate inert gas; an oxygen concentration sensor; an actuator of the inert gas generator configured to release the generated inert gas; a plurality of signal-connected controller modules configured to execute one or more regulating functions, wherein the regulating functions are distributed to at least two of the plurality of signal-connected controller modules; an area controller of the plurality of signal-connected controller modules configured to use the oxygen concentration sensor for one or more of monitoring the oxygen concentration level in an enclosed monitored area or regulating the oxygen concentration level in the enclosed protected area by releasing the inert gas; a process controller of the plurality of signal-connected controller modules configured to regulate inert gas generation by the inert gas generator, and is a master controller of the plurality of signal-connected controller modules configured to one or more of coordinate communication between components of the oxygen-reducing system or coordinate communication to points external to the oxygen-reducing system.

15. The oxygen-reducing system of claim 14, wherein for each of a plurality of enclosed protected areas, at least one of the plurality of signal-connected controller modules configured as the area controller is assigned to each enclosed protected area for regulating the oxygen concentration level in the respective enclosed protected area.

16. The oxygen-reducing system of claim 14, wherein for each of a plurality of enclosed monitored areas, at least one of the plurality of signal-connected controller modules configured as the area controller is assigned to each enclosed monitored area for monitoring the oxygen concentration level in the respective enclosed monitored area.

17. The oxygen-reducing system of claim 14, wherein a combination controller is configured to perform the regulating functions of at least two of the master controller, the area controller, or the process controller.

18. The oxygen-reducing system of claim 14, wherein one or more of the process controller or the master controller is configured to distribute inert gas according to a predetermined criteria such that multiple inert gas generators run for essentially a same length of time.

19. An oxygen-reducing system configured to lower and maintain an oxygen concentration level in an enclosed protected area, comprising: an inert gas generator configured to generate inert gas; an oxygen concentration sensor; an actuator of the inert gas generator configured to release the generated inert gas; a plurality of signal-connected controller modules configured to execute one or more regulating functions, wherein the plurality of signal-connected controller modules are self-configuring so that regulating functions are automatically activated based on one or more of (a) a type and mode of operation of connected devices or (ii) input/output interfaces, wherein different regulating functions are assigned to different signal-connected controller modules during operation, and wherein in response to a failure of a first signal-connected controller module, a second signal-connected controller module is configured to automatically take over regulating functions from the first signal-connected controller module; an area controller of the plurality of signal-connected controller modules configured to use the oxygen concentration sensor to one or more of monitor the oxygen concentration level in an enclosed monitored area or regulate the oxygen concentration level in the enclosed protected area by releasing the inert gas; a process controller of the plurality of signal-connected controller modules configured to regulate inert gas generation by the inert gas generator; and a master controller of the plurality of signal-connected controller modules configured to one or more of coordinate communication between components of the oxygen-reducing system or coordinate communication to points external to the oxygen-reducing system.

Description

(1) The invention will be explained in greater detail below on the basis of the accompanying schematic drawings. Shown therein:

(2) FIG. 1a a schematic representation of an oxygen-reducing system having a control and regulating system pursuant to the prior art;

(3) FIG. 1b a schematic representation reduced to the signal connections of a control and regulating system of an oxygen-reducing system pursuant to the prior art;

(4) FIG. 2a a schematic representation of an oxygen-reducing system having a control and regulating system according to the invention pursuant to one preferential embodiment with two controller modules;

(5) FIG. 2b a schematic representation reduced to the signal connections of an inventive control and regulating system of an oxygen-reducing system pursuant to one preferential embodiment with two controller modules;

(6) FIG. 3a a schematic representation of an oxygen-reducing system having an inventive control and regulating system pursuant to a further preferential embodiment with four controller modules;

(7) FIG. 3b a schematic representation reduced to the signal connections of an inventive control and regulating system of an oxygen-reducing system pursuant to one preferential embodiment with four controller modules;

(8) FIG. 4a a schematic representation of an oxygen-reducing system having an inventive control and regulating system pursuant to a further preferential embodiment with six controller modules;

(9) FIG. 4b a schematic representation reduced to the signal connections of an inventive control and regulating system of an oxygen-reducing system pursuant to one preferential embodiment with six controller modules;

(10) FIG. 5a a schematic representation of an oxygen-reducing system having an inventive control and regulating system pursuant to a further preferential embodiment with six controller modules and field stub lines;

(11) FIG. 5b a schematic representation reduced to the signal connections of an oxygen-reducing system having an inventive control and regulating system pursuant to a further preferential embodiment with six controller modules and field stub lines; and

(12) FIG. 6 a schematic representation of an oxygen-reducing system having an inventive control and regulating system pursuant to a further preferential embodiment with enhanced communication.

(13) FIGS. 1a, 2a, 3a, 4a, 5a and 6 basically show similarly structured oxygen-reducing systems which serve as preventive fire protection systems for monitoring and regulating the oxygen concentration in protected areas 10. The most important components of the oxygen-reducing system are inert gas generators 30a, 30b. The inert gas generator 30a in the figures is realized as a membrane nitrogen generator and essentially comprises: a compressor 33 for compressing ambient air; a pressure sensor 31b for detecting the pressure of the compressed ambient air; a membrane 36 for separating the ambient air into oxygen-enriched air, which is discharged via a not-shown line, and nitrogen-enriched air, which is introduced into one of the protected areas 10 via a nitrogen line 37; and an oxygen concentration sensor 31a for measuring the residual oxygen content of the nitrogen-enriched air.

(14) Instead of or in addition to the oxygen concentration sensor 31a, a volumetric flow sensor can optionally be provided downstream of the membrane 36.

(15) The inert gas generator 30b in the figures is realized as a pressure swing adsorption nitrogen generator and essentially comprises: a compressor 33 for compressing ambient air; a pressure sensor 31b for detecting the pressure of the compressed ambient air; an adsorbent container 34, for example having a carbon molecular sieve, for separating the ambient air into oxygen-enriched air, which is discharged via a not-shown line, and nitrogen-enriched air, which is introduced into one of the protected areas 10 via a nitrogen line 37; and a buffer tank 35 for the temporary storage of the nitrogen-enriched air; valves 32 for alternatingly feeding the ambient air into the adsorbent container 34 or the nitrogen-enriched air from the adsorbent container 34 into the buffer tank 35 respectively; a pressure sensor 31b for detecting the pressure of the nitrogen-enriched air; and an oxygen concentration sensor 31a for measuring the residual oxygen content of the nitrogen-enriched air.

(16) Instead of or in addition to the oxygen concentration sensor 31a, a volumetric flow sensor can optionally be provided downstream of the buffer tank 35.

(17) The nitrogen-enriched air generated by the inert gas generators 30a, 30b is introduced as needed into the protected areas 10 via selector valves 41 in order to lower the oxygen content of the air in the protected areas 10. The oxygen content in the protected areas 10 as well as also in, for example, monitored rooms 11, e.g. in an adjacent hallway or in machine rooms 12 in which the inert gas generators 30a, 30b are located, is monitored by oxygen concentration sensors 40. In the event of critical environmental conditions, for example an oxygen content falling below a threshold value, a means of alarm 42 is activated in the affected area and potentially also in other areas in order to alert any persons who might be present. Of course, further sensors, e.g. temperature, moisture and gas sensors, are also conceivable in the protected areas 10, monitored areas 11 and machine rooms 12 as well as on the inert gas generators 30a, 30b. Other types of actuators, such as actuating drives, can likewise be part of the oxygen-reducing system. Control and regulating functions of the oxygen-reducing system can be monitored and governed via a control panel 43 as a human/machine interface.

(18) FIGS. 1a to 6 show different control and regulating systems for enabling the operation of the oxygen-reducing system. FIGS. 1a, 2a, 3a, 4a and 5a thereby show the control and regulating systems in conjunction with the further components of the oxygen-reducing system. In contrast, FIGS. 1b, 2b, 3b, 4b and 5b only show the signal connections of the control and regulating systems to sensors and actuators. They thereby serve in providing a better overview of the architecture of the respective control and regulating system.

(19) FIGS. 1a and 1b show a control and regulating system of an oxygen-reducing system pursuant to the prior art. Such systems for oxygen-reducing systems have to date been realized with a control center 20 connected in a star layout to the individual sensors 31a, 31b, 40, actuators 32, 33, 41 and means of alarm 42 by means of field stub lines 50. As can be clearly seen from FIGS. 1a and 1b, the individual connections between the control center 20 and the sensors 31a, 31b, 40, actuators 32, 33, 41 and alarm means 42 result in a complex architecture of lines with, inter alia, a large number of individual lines, long line lengths and resulting increased susceptibility to failure. The control center 20 itself needs to be configured with high computing power and numerous interfaces in order to be able to reliably perform all the control and regulating functions. Subsequent expansions and reconfigurations, as well as troubleshooting in the event of failure messages, prove laborious as well as time-consuming and costly.

(20) FIGS. 2a to 6 show variants of the control and regulating system according to the invention. All the exemplary embodiments of the invention comprise at least two controller modules 21, 22, 23, 24, 25 to which one or more regulating functions of the control and regulating system are decentrally distributed. The controller modules 21, 22, 23, 24, 25 are preferably of standardized construction, thus essentially having identical hardware components. Each controller module 21, 22, 23, 24, 25 in particular comprises similar or comparable controllers as well as at least partially similar or comparable communication interfaces. The controller modules 21, 22, 23, 24, 25 are signal-connected to one another and are preferably of differing configuration. In particular, different regulating functions can be divided among the individual controller modules 21, 22, 23, 24, 25.

(21) The exemplary embodiment according to FIGS. 2a, 2b shows for example a control and regulating system having two controller modules 22, 24. A combination controller 24 which combines the regulating functions of an area controller and a master controller is thereby in particular provided and, as a consequence, takes over the monitoring of the oxygen concentration levels in the protected areas 10 on the one hand and, on the other hand, the coordination of the communication between the controller modules 22, 24 and the further components of the oxygen-reducing system. The further controller module is a controller module configured as a process controller 22 for controlling or respectively regulating the generation of inert gas by the two inert gas generators 30a, 30b. The combination controller 24 and the process controller 22 are spatially separated from one another. The process controller 22 is located in the machine room 12 in which the two inert gas generators 30a, 30b are also arranged. The combination controller 24, on the other hand, is located in a separate utility room 13. The spatial separation of the two controller modules 22, 24 increases system stability, shortens line lengths and improves accessibility to the controller modules 22, 24.

(22) For its area controller function, the combination controller 24 is connected to oxygen concentration sensors 40 and alarm means 42 in the protected areas 10 as well as the monitored area 11. With the aid of the oxygen concentration sensors 40, the combination controller 24 determines the oxygen concentration in the atmosphere of the protected areas 10 and the monitored area 11. As regards the regulation of the oxygen concentration in the protected areas 10, the combination controller 24 communicates a nitrogen requirement to the process controller 22, which adapts the inert gas generation to the communicated nitrogen requirement and coordinates the introduction of the nitrogen-enriched air, for example via activation of the selector valves 41. Alternatively, the selector valves can be activated by an area controller as soon as same detects a demand for nitrogen. The process controller 22 is in turn signal-connected to pressure and oxygen concentration sensors 31a, 31b as well as actuators such as the compressors 33 and valves 32 of the inert gas generator 30a, 30b in order to control and regulate the inert gas generation. The process controller 22 is however not limited to the function of the generation of inert gas; in the present exemplary embodiment, it also takes on an area controller function for the machine room 12 by monitoring the oxygen concentration of the machine room 12 via an oxygen concentration sensor 40 and, if necessary, activating a means of alarm 42 in the machine room 12 upon the falling short of an oxygen threshold value suggestive of inert gas generator 30a, 30b leakage. This highly individual configuration of the controller modules 22, 24, adaptable to a wide variety of requirements, enables the functions of the control and regulating system to be distributed on a need-based and optimal basis in respect of the line architecture.

(23) In contrast to the prior art, the connecting paths between the controller modules 22, 24 and the associated sensors 31a, 31b, 40, actuators 32, 33, 41 and alarm means 42 are realized as field ring lines 51. The ring-shaped configuration can reduce line paths and the redundant connecting paths furthermore increases system stability. Communication via the field ring lines 51 can ensue for example via a CAN bus or via RS-485 with CANopen, Profibus or Modbus RTU protocol. The combination controller 24 and the process controller 22 additionally communicate via an additional controller ring line 52, realized for example as an Ethernet connection. The combination controller 24 is furthermore in a stub connection with the control panel 43 via which a user can monitor and govern the control and regulating functions.

(24) FIGS. 3a, 3b show a further exemplary embodiment of the invention, wherein a total of four controller modules 21, 25 are provided. Two respective controller modules form one master controller 21. These are signal-connected to each other, in particular by a controller ring line 52. Two combination controllers 25, which in this exemplary embodiment combine the functions of an area controller and a process controller, are additionally disposed in the controller ring line 52. The master controller 21 and the combination controller 25 are in this case designed as redundant controller modules 21, 25, each forming one respective controller group and providing increased system stability due to the redundant design. The combination controllers 25 are signal-connected to the sensors 31a, 31b, 40, actuators 32, 33, 41 and alarm means 42 of the inert gas generators 30a, 30b, the protected areas 10, the monitored area 11 and the machine room 12 via field ring lines 51. They thus coordinate the generation of inert gas by the inert gas generators 30a, 30b as well as the monitoring and regulating of the oxygen concentration in the individual areas 10, 11, 12. On the other hand, the master controllers 21 in the utility room 13 are responsible for coordinating controller module 21, 25 communication as well as the displaying of failure and alarm messages or respectively receiving user inputs via the control panel 43. The exemplary embodiment according to FIGS. 3a, 3b is characterized on the whole by high redundancy and thus operational reliability. Should one of the controller modules 21, 25 fail, a controller module 21, 25 not only of the same construction but also the same configuration can take over the entirety of functions of the other controller module 21, 25. Due to the two respective ring lines shared by both redundant controller modules 21, 25, each controller module 21, 25 can directly access the sensors 31a, 31b, 40, actuators 32, 33, 41 and alarm means 42 of the other controller module 21, 25 without any detour.

(25) FIGS. 4a, 4b show a similar control and regulating system architecture pursuant to a further preferred exemplary embodiment. Specifically, the control and regulating system according to FIG. 4 likewise comprises two master controllers 21 in utility room 13 which are signal-connected to one another and form a redundant controller group. The master controllers 21 are responsible for coordinating controller module 21, 22, 23 communication as well as the displaying of failure and alarm messages or respectively receiving user inputs via the control panel 43. In contrast to the exemplary embodiment according to FIGS. 3a, 3b, no combination controller is provided. Instead, the control and regulating system comprises two separate area controllers 23 as well as two separate process controllers 22. The area controllers 23 serve in the monitoring of the oxygen concentration in the protected areas 10 and in the monitored area 11. The area controllers 23 are to this end signal-connected to oxygen concentration sensors 40 in areas 10, 11 and can likewise activate alarm means 42 located in these areas 10, 11 in the event of a malfunction or alarm such as for instance an unhealthy oxygen concentration level. The process controllers 22 serve in the control and regulating of the generation of inert gas by the inert gas generators 30a, 30b and are to that end signal-connected to the pressure and oxygen concentration sensors 31a, 31b as well as to the valves 32, the compressors 33 and the selector valves 41. Moreover, in the exemplary embodiment shown, they fulfill an additional area controller function as relates to the machine room 12. The area controllers 23 and the process controllers 22 do not communicate directly with one another but are instead jointly connected to the master controller 21 via two controller ring lines 52. It thereby becomes clear that the master controllers 21 assume the coordinating of the communication, for example processing a nitrogen requirement determined by the area controllers 23 and relaying it to the process controllers 22. The exemplary embodiment according to FIGS. 4a and 4b is not only characterized by even higher redundancy and system stability compared to the exemplary embodiment in FIGS. 3a, 3b, but also shows particular suitability for very large or complex oxygen-reducing systems with high control and regulation needs at the inert gas generation, area monitoring and higher-order communication levels.

(26) The exemplary embodiment according to FIGS. 5a, 5b differs from the exemplary embodiment according to FIGS. 4a, 4b by the sensors 40 and actuators 42, or inert gas generators 30a, 30b respectively, being connected to the area controllers 23/process controllers 22. Specifically, field stub lines 50 are provided in this exemplary embodiment instead of field ring lines. This avoids the doubled connection of sensors and actuators and is thus economic by comparison. Moreover, the selector valves 41 are activated by the area controllers 23 in this example.

(27) FIG. 6 shows an enhancement of the exemplary embodiment according to FIGS. 5a, 5b. Specifically, the control and regulating system is of similar design to the exemplary embodiment according to FIGS. 5a, 5b. In total, two redundantly designed master controllers 21, two redundantly designed area controllers 23 and two redundantly designed process controllers 22 are provided. The area controllers 23 and process controllers 22 are signal-connected to the master controllers 21 via controller ring lines 52.

(28) FIG. 6 additionally shows further communication interfaces which can be provided on at least one of the master controllers 21. For example, the master controller 21 can have an input interface for a weather station 67. Current environmental conditions of the ambient atmosphere, e.g. wind speeds, can thus be incorporated into the regulation of the oxygen-reducing system. A signal output which communicates with a continuously manned location 68 can furthermore be provided. Doing so enables alarm and failure messages to be forwarded to suitable recipients for effecting countermeasures.

(29) Additional communication functions for remote maintenance or remote configuration can furthermore be provided. For example, a communication switching unit (“switch”) 60 controls the communication to different external devices such as for instance a remote diagnosis module 63 which in turn can be connected to an external remote support PC 66 via a WLAN router 64 or via the internet 65 or to a local support PC 62. A likewise locally located data storage and evaluation unit 61, e.g. an industrial PC or server, can serve in the logging of all operational data and in particular in the long-term evaluation of system data such as for instance control parameters, sensor data, environmental data, energy consumption data and/or status, failure and alarm messages. This thereby enables for example predictive maintenance or the determining of relevant maintenance intervals.

(30) In general, the control and regulating system according to the above-described exemplary embodiments can be expanded virtually at will. In particular, multiple master controllers 21, multiple area controllers 23, multiple process controllers 22 and/or multiple combination controllers 24, 25 can be provided.

LIST OF REFERENCE NUMERALS

(31) 10 protected area 11 monitored area 12 machine room 13 utility room 20 control center 21 master controller 22 process controller 23 area controller 24 combination controller (master/area controller) 25 combination controller (process/area controller) 30a membrane nitrogen generator 30b pressure swing adsorption nitrogen generator 31a oxygen concentration sensor 31b pressure sensor 32 valve 33 compressor 34 adsorbent container 35 buffer tank 36 membrane 37 nitrogen line 40 oxygen concentration sensor 41 selector valve 42 alarm means 43 control panel 50 field stub line 51 field ring line 52 controller ring line 60 switch 61 industrial PC 62 support PC 63 remote diagnosis module 64 WLAN router 65 internet 66 remote support PC 67 weather station 68 continuously manned location