A CO2 compression, gas supply process control system and control method

Abstract

The application belongs to the compressor field, and particularly relates to a novel CO2 compression and gas supply process control system and a control method. The system comprises a front-end gas supply device, a CO2 compressor unit, a CO2 drying module, a CO2 destination selection module, a rear-end user pipe network, a CO2 liquefaction auxiliary machine sled module, a liquid CO2 storage tank storage module, a CO2 gasification sled module, and a remote distributed control system (DCS) and on-site PLC control. The structure can consider the pressure of the CO2 compressor inlet and outlet, and ensure the long-term safe and stable operation of the CO2 compressor.

Description

Technical Field

[0001] This invention belongs to the field of compressors, specifically relating to a CO2 compression and gas supply process control system and control method. Background Technology

[0002] Currently, flue gas carbon capture devices are gradually being commercialized. These devices typically include a CO2 compressor downstream to increase the gas supply pressure and meet the gas requirements of end users and liquefaction systems. However, existing CO2 compressors in carbon capture systems experience significant inlet pressure fluctuations, which can easily lead to compressor shutdown. Furthermore, the gas supply conditions from the compressor outlet to the end user are complex, with large pressure fluctuations in the main gas supply line. This necessitates continuous adjustment of the CO2 compressor's capacity to match the gas demand of downstream users. In actual operation, existing CO2 compressor controls struggle to accommodate both inlet and outlet pressure fluctuations, impacting the long-term safe and stable operation of the CO2 compressor.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a CO2 compression and gas supply process control system and method. The structure of this invention can balance the inlet and outlet pressures of the CO2 compressor, ensuring the long-term safe and stable operation of the CO2 compressor.

[0005] This invention includes the following technical solutions:

[0006] This invention provides a CO2 compression and gas supply process control system, including a front-end gas supply device, a CO2 compressor unit, a CO2 drying module, a CO2 destination selection module, a back-end user pipeline network, a CO2 liquefaction auxiliary machine skid module, a liquid CO2 storage tank module, a CO2 gasification skid module, a remote distributed control system (DCS), and local PLC control.

[0007] The front-end gas supply device is connected to the CO2 compressor unit, the CO2 compressor unit is connected to the CO2 drying module, the CO2 drying module is connected to the CO2 destination selection module, the CO2 destination selection module is connected to the back-end user pipeline network and the CO2 liquefaction auxiliary machine skid module, the CO2 liquefaction auxiliary machine skid module is connected to the liquid CO2 storage tank module, the liquid CO2 storage tank module is connected to the CO2 vaporization skid module, and the CO2 vaporization skid module is connected to the back-end user pipeline network.

[0008] Furthermore, the front-end gas supply device is connected to the CO2 compressor unit through a first pipeline, on which a temperature sensor, a pressure sensor, and a humidity sensor are installed.

[0009] Further, the CO2 compressor set is connected with the CO2 destination selection module through a second pipeline, and a temperature sensor, a pressure sensor and a flow sensor are arranged on the second pipeline, and the CO2 compressor set is provided with a vibration sensor and a slide valve adjusting device.

[0010] Further, the CO2 compressor set and the CO2 drying module are connected through a third pipeline, and a temperature sensor, a pressure sensor and a differential pressure sensor are arranged on the third pipeline.

[0011] Further, the liquid CO2 storage tank storage system is provided with a flow sensor, a temperature sensor and a pressure sensor.

[0012] Further, the CO2 gasification pry module is provided with a flow sensor, a temperature sensor and a pressure sensor on the gas outlet main pipe.

[0013] Further, the front end of the back-end user pipe network is provided with an electric regulating valve, a temperature sensor, a pressure sensor and a humidity sensor, and the tail end is provided with a flow sensor, a pressure sensor, a CO2 quality sensor and a humidity sensor.

[0014] Further, the remote distributed control system DCS is connected with the on-site PLC control, and the on-site PLC control controls the CO2 compressor set and the CO2 destination selection module.

[0015] The application also provides a control method of the CO2 compression and gas supply process control system, characterized by comprising the system, and the method comprises the following steps:

[0016] The CO2 compressor outlet pressure control, according to the CO2 pressure working range of the front-end gas supply device, the CO2 gas requirement of the collected back-end user pipe network, and the hourly, daily and monthly use data, the CO2 compressor set is selected comprehensively, the CO2 compressor set is selected as 2:1 standby configuration, and the target working pressure of the CO2 compressor set outlet is set; the remote distributed control system DCS and the on-site PLC control are connected in series, the remote distributed control system DCS is used as feedback regulation according to the target working pressure of the outlet, the historical data of the back-end user pipe network is used as predictive feedforward control, the number of CO2 compressors and the regulating opening of the slide valve adjusting device are controlled, the stability of the CO2 compressor outlet pressure is ensured, the CO2 compressor works in a safe and energy-saving state; the running state of the CO2 compressor is monitored in real time, the compressor is programmed and marshaled in sequence, the labor intensity of manual operation of the operator is reduced, the compressor can be automatically started and stopped, and the automatic switching is realized in the interlock protection state, and the service life of the compressor is ensured.

[0017] The back-end user pipe network pressure and flow adjustment control, the electric switch valve, the electric adjustment valve, the temperature sensor, the pressure sensor and the humidity sensor arranged at the front end of the back-end user pipe network, and the flow sensor, the pressure sensor, the CO2 quality sensor and the humidity sensor arranged at the end are uniformly incorporated into a remote distributed control system (DCS) for control, and the dynamic PID adjustment of the electric adjustment valve opening degree is carried out according to the front-end pressure, flow and end pressure, flow of the back-end user pipe network; the control pressure is indirectly used to control the flow, and the end pressure and flow of the user pipe network are stably ensured to be in the use working interval.

[0018] The CO2 drying module outlet main pipe pressure protection control is uniformly incorporated into a remote distributed control system (DCS) for control, the outlet main pipe is provided with a remote monitoring instrument for interlocked protection pressure, when the pressure rises to a predetermined set value, the CO2 direction selection module interlocks to act to deliver excessive CO2 to the CO2 liquefaction auxiliary machine skid module for liquefaction storage; the main pipe pressure is ensured to work in a normal working range; when the main pipe pressure continues to rise to a system protection action pressure, an emptying electric valve is automatically opened in emergency to release pressure for the safety of system work.

[0019] By adopting the technical scheme, the present application has the following advantages:

[0020] 1. The structure of the present application can consider the pressures at the inlet and outlet of the CO2 compressor, and ensure the long-term safe and stable operation of the CO2 compressor.

[0021] 2. The present application can monitor the running state of the CO2 compressor in real time, and can program and control the compressor to reduce the labor intensity of manual operation of the operator, so that the compressor can be automatically started and stopped and switched automatically in the interlocking protection, and the service life of the compressor is ensured.

[0022] 3. The present application can adjust the pressure and flow of the back-end user pipe network, and ensure that the end pressure and flow of the user pipe network are stable in the use working interval.

[0023] 4. The present application can collect and analyze the user-side gas data and the front-end gas supply device pressure data in real time by four basic control main circuits, and can dynamically adjust the internal diagnostic parameters of the control system to ensure the stability of the CO2 compressor outlet pressure and the back-end user pipe network gas, and overcome the influence of the CO2 compressor inlet and the back-end user pipe network pressure fluctuation on the system. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present application, and the other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0025] Figure 1 The structure diagram of the user gas supply stabilizing system of the CO2 compressor in the embodiment of the present application;

[0026] In the figure: 10-front end gas supply device, 20-CO2 compressor group, 30-CO2 drying module, 40-CO2 destination selection module, 50-rear end user pipe network, 60-CO2 liquefaction auxiliary machine sled module, 70-liquid CO2 storage tank storage module, 80-CO2 gasification sled module. DETAILED DESCRIPTION

[0027] The following description provides many different embodiments, or examples, for implementing different features of the application. Specific examples are described in the following to describe the elements and arrangements of the present application, which are only used to express the present application, and are only examples, not to limit the present application.

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present application.

[0029] The present embodiment provides a CO2 compression and gas supply process control system, which comprises a front end gas supply device 10, a CO2 compressor group 20, a CO2 drying module 30, a CO2 destination selection module 40, a rear end user pipe network 50, a CO2 liquefaction auxiliary machine sled module 60, a liquid CO2 storage tank storage module 70, a CO2 gasification sled module 80 and a remote distributed control system DCS and on-site PLC control.

[0030] The front-end gas supply device 10 is connected with the CO2 compressor set 20, the CO2 compressor set 20 is connected with the CO2 drying module 30, the CO2 drying module 30 is connected with the CO2 destination selection module 40, the CO2 destination selection module 40 is connected with the rear-end user pipe network 50 and the CO2 liquefaction auxiliary machine sled module 60 respectively, the CO2 liquefaction auxiliary machine sled module 60 is connected with the liquid CO2 tank storage module 70, the liquid CO2 tank storage module 70 is connected with the CO2 gasification sled module 80, and the CO2 gasification sled module 80 is connected with the rear-end user pipe network 50.

[0031] Further, the front-end gas supply device 10 is connected with the CO2 compressor set 20 through a first pipeline, and the first pipeline is provided with a temperature sensor, a pressure sensor and a humidity sensor.

[0032] Further, the CO2 compressor set 20 is connected with the CO2 destination selection module 40 through a second pipeline, and the second pipeline is provided with a temperature sensor, a pressure sensor and a flow sensor, and the CO2 compressor set 20 is provided with a vibration sensor and a slide valve adjusting device.

[0033] Further, the CO2 compressor set 20 and the CO2 drying module 30 are connected through a third pipeline, and the third pipeline is provided with a temperature sensor, a pressure sensor and a differential pressure sensor.

[0034] Further, the liquid CO2 tank storage system is provided with a flow sensor, a temperature sensor and a pressure sensor.

[0035] Further, the CO2 gasification sled module is provided with a flow sensor, a temperature sensor and a pressure sensor on the gas outlet main pipe.

[0036] Further, the rear-end user pipe network is provided with an electric regulating valve, a temperature sensor, a pressure sensor and a humidity sensor at the front end, and is provided with a flow sensor, a pressure sensor, a CO2 quality sensor and a humidity sensor at the tail end.

[0037] Further, the remote distributed control system DCS is connected with the on-site PLC control, and the on-site PLC control controls the CO2 compressor set 20 and the CO2 destination selection module 40.

[0038] It should be noted that the above-mentioned sensors all send detection signals to the remote distributed control system DCS.

[0039] The embodiment also provides a control method of the CO2 compression and gas supply process control system, characterized in that the method comprises the system described above, and the method comprises the following steps:

[0040] The CO2 compressor outlet pressure control is comprehensively selected according to the CO2 pressure working range of the front-end gas supply device 10 and the CO2 gas requirement of the back-end user pipe network 50 and the hourly, daily and monthly use data, the CO2 compressor set 20 is selected in two and one standby configuration, and the CO2 compressor set 20 outlet target working pressure is set; the remote distributed control system DCS and the local PLC control are connected in series, the remote distributed control system DCS is adjusted according to the outlet target working pressure as feedback, the back-end user pipe network 50 gas historical data is used as predictive feedforward control, the number of CO2 compressors running and the opening degree of the slide valve adjusting device are controlled, the CO2 compressor outlet pressure is stabilized, and the CO2 compressor works in a safe and energy-saving state; the running state of the CO2 compressor is monitored in real time, the compressor is programmed and controlled, the labor intensity of manual operation of the running personnel is reduced, the compressor can be automatically started and stopped and automatically switched during interlocking protection, and the service life of the compressor is ensured.

[0041] The back-end user pipe network 50 pressure and flow regulation control unifies the front-end electrically operated on-off valve, the electrically operated regulating valve, the temperature sensor, the pressure sensor and the humidity sensor and the end flow sensor, the pressure sensor, the CO2 quality sensor and the humidity sensor into the remote distributed control system DCS for control, dynamically adjusts the electrically operated regulating valve opening degree according to the front-end pressure, flow and the end pressure, flow of the back-end user pipe network 50, controls the pressure indirectly to control the flow, and stabilizes the user pipe network end pressure and flow in the use working interval.

[0042] The CO2 drying module 30 outlet header pressure protection control is unified into the remote distributed control system DCS for control, the outlet header is provided with an interlocked protection pressure remote monitoring instrument, when the pressure rises to a predetermined set value, the CO2 direction selection module 40 interlocks to move and transports excessive CO2 to the CO2 liquefaction auxiliary machine jacking block module 60 for liquefaction storage, the header pressure is ensured to work in a normal working range, and when the header pressure continues to rise to a system protection action pressure, an emptying electric valve is automatically opened to release pressure for system working safety.

[0043] When the front-end electrically operated regulating valve of the back-end user pipe network 50 reaches the maximum regulating range and cannot meet the end working pressure demand of the back-end user pipe network 50, the CO2 gasification jacking block module 80 is used to supply gas to the user pipe network to stabilize the gas supply pressure. The CO2 gasification jacking block module 80 is respectively provided with three sub-regulation control loops, one of which is provided with an electrically operated regulating valve, a temperature, a pressure and a flow measuring device to control the pressure transported to the back-end user pipe network 50, one of which is provided with an electrically operated regulating valve and a temperature measuring device to control the gasification system temperature to work in a set range, and one of which is provided with an electrically operated regulating valve and a pressure monitoring device to ensure that the gasification system and the liquid CO2 storage tank storage module 70 pressure keep balance.

[0044] Through the above four basic control main loops, a remote distributed control system (DCS) is used in conjunction with local PLC control to collect and analyze user-side gas consumption data and front-end gas supply device 10 pressure data in real time. The internal diagnostic parameters of the control system are dynamically adjusted to ensure the stability of the outlet pressure of CO2 compressor unit 20 and the gas consumption of the downstream user pipeline network 50, and to overcome the impact of pressure fluctuations at the inlet of CO2 compressor unit 20 and the downstream user pipeline network 50 on the system.

[0045] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for a CO2 compression and gas supply process control system, characterized in that, The method is as follows: The CO2 compressor outlet pressure control is based on the CO2 pressure working range of the front-end gas supply device (10) and the CO2 gas consumption requirements and hourly, daily and monthly usage data collected from the back-end user pipeline network (50) to comprehensively select the CO2 compressor unit (20). The CO2 compressor unit (20) is selected with a 2-operation and 1-standby configuration, and the target working pressure of the CO2 compressor unit (20) outlet is set. The remote distributed control system (DCS) is connected in series with the local PLC control. The remote distributed control system (DCS) uses the target working pressure of the outlet as feedback adjustment, and the gas consumption history data of the back-end user pipeline network (50) is used as prediction feedforward control to control the number of CO2 compressors in operation and the opening degree of the slide valve adjustment device to ensure that the CO2 compressor outlet pressure is stable and the CO2 compressor operates in a safe and energy-saving state. The pressure and flow regulation control of the back-end user pipeline (50) integrates the electric switching valve, electric regulating valve, temperature sensor, pressure sensor and humidity sensor set at the front end of the back-end user pipeline (50), and the flow sensor, pressure sensor, CO2 quality sensor and humidity sensor set at the end into the remote distributed control system DCS for control. The opening degree of the electric regulating valve is dynamically adjusted by PID according to the pressure and flow of the front end and the pressure and flow of the back-end user pipeline (50). The outlet main pipe pressure protection control of the CO2 drying module (30) is uniformly incorporated into the remote distributed control system (DCS) for control. The outlet main pipe is equipped with a remote monitoring instrument for interlock protection pressure. When the pressure rises to the predetermined set value, the CO2 destination selection module (40) interlocks to send excess CO2 to the CO2 liquefaction auxiliary skid module (60) for liquefaction storage. When the electric regulating valve at the front end of the back-end user pipeline (50) reaches its maximum regulating range and cannot meet the working pressure requirements at the end of the back-end user pipeline (50), the CO2 gasification skid module (80) supplies gas to the user pipeline to ensure stable gas supply pressure. The CO2 gasification skid module (80) is equipped with three sub-regulation control loops. One loop is equipped with an electric regulating valve, temperature, pressure and flow measurement device to control the pressure delivered to the back-end user pipeline (50). Another loop is equipped with an electric regulating valve and temperature measurement device to control the temperature of the gasification system to work in the set area. The third loop is equipped with an electric regulating valve and pressure monitoring device to ensure that the pressure of the gasification system and the liquid CO2 storage tank module (70) are kept in balance. Among them, the front-end gas supply device (10) is connected to the CO2 compressor unit (20), the CO2 compressor unit (20) is connected to the CO2 drying module (30), the CO2 drying module (30) is connected to the CO2 destination selection module (40), the CO2 destination selection module (40) is connected to the back-end user pipeline (50) and the CO2 liquefaction auxiliary machine skid module (60) respectively, the CO2 liquefaction auxiliary machine skid module (60) is connected to the liquid CO2 storage tank module (70), the liquid CO2 storage tank module (70) is connected to the CO2 vaporization skid module (80), and the CO2 vaporization skid module (80) is connected to the back-end user pipeline (50).

2. The control method for a CO2 compression and gas supply process control system as described in claim 1, characterized in that, The front-end gas supply device (10) is connected to the CO2 compressor unit (20) through a first pipeline, on which a temperature sensor, a pressure sensor and a humidity sensor are installed.

3. The control method of the CO2 compression and gas supply process control system as described in claim 1, wherein the CO2 compressor unit (20) is connected to the CO2 destination selection module (40) through a second pipeline, wherein a temperature sensor, a pressure sensor and a flow sensor are provided on the second pipeline, and the CO2 compressor unit (20) is equipped with a vibration sensor and a slide valve adjustment device.

4. The control method for a CO2 compression and gas supply process control system as described in claim 1, characterized in that, The CO2 compressor unit (20) and the CO2 drying module (30) are connected by a third pipe, on which a temperature sensor, a pressure sensor and a differential pressure sensor are installed.

5. The control method for a CO2 compression and gas supply process control system as described in claim 1, characterized in that, The liquid CO2 storage tank system is equipped with a flow sensor, a temperature sensor, and a pressure sensor.

6. The control method for a CO2 compression and gas supply process control system as described in claim 1, characterized in that, The CO2 gasification skid module is equipped with a flow sensor, a temperature sensor, and a pressure sensor on its outlet header.

7. The control method for a CO2 compression and gas supply process control system as described in claim 1, characterized in that, The back-end user pipeline is equipped with an electric regulating valve, a temperature sensor, a pressure sensor, and a humidity sensor at the front end, and a flow sensor, a pressure sensor, a CO2 quality sensor, and a humidity sensor at the end.

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