Modular logic for automatic switching of a circulating water system operational mode

Abstract

The application discloses a kind of modular logic settings of circulating water system operating mode automatic switching, using modular design idea, the contents such as circulating water pump start-stop, valve opening adjustment, system pressure stabilization involved in circulating water system operating mode switching are designed as automatic sequence control logic according to switching process requirements, with system pressure stabilization as core, according to switching direction requirement, independently carry out circulating water pump start-stop operation, cooperatively adjust pump body and pipeline valve opening, simultaneously introduce pressure variation trend, valve characteristic curve as feedforward determination condition, to realize the early prediction and accurate control of operation node, and all operation items are modularized, finally in the form of one-key switching window, to realize the purpose that operating personnel carries out circulating water operating mode one-key switching according to the change direction of working condition.

Description

Technical Field

[0001] This invention relates to the technical field of units with differentiated configurations of large and small pumps for circulating water, and in particular to a modular logic setting for automatic switching of operating modes in a circulating water system. Background Technology

[0002] A gas-steam combined cycle cogeneration and peak-shaving power plant combines a gas turbine and a steam turbine into a combined cycle unit. The gas turbine is a high-efficiency, high-power, heavy-duty gas turbine with rapid start-up and shutdown capabilities and rapid load change capabilities. The steam turbine is a heating turbine that can achieve three operating modes: pure condensing, extraction condensing, and back pressure. The unit as a whole exhibits the operating characteristics of peak shaving in summer and heating in winter.

[0003] To accommodate the flexible and varied operating modes of the unit, the circulating water system is designed with differentiated configurations for large and small pumps. There are three modes: large pump operating alone, small pump operating alone, and large and small pumps operating simultaneously. Correspondingly, there are six switching modes: large pump switching to small pump, small pump switching to large pump, large pump switching to both pumps, small pump switching to both pumps, both pumps switching to large pump, and both pumps switching to small pump.

[0004] In existing technologies, switching the operation mode of a circulating water system is a complex systemic operation with a long process, numerous operational items, and heavy workload for operators. Many operational items need to be completed in a short period of time, resulting in a tight operational rhythm and high operational risks. The control of operational nodes depends on the judgment of operators, and the rapid changes in system parameters contradict the relative lag between subjective judgment and manual operation, increasing the instability factors of the switching operation. The frequent changes in the operating conditions of cogeneration peak-shaving units and the frequent switching of circulating water system operation modes further increase the workload and operational risks, creating long-term safety hazards for the stable operation of the units. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a modular logic setting for automatic switching of the operation mode of a circulating water system, including the following steps: wherein, When switching from the large pump to the small pump, firstly, it is determined that the large pump is operating normally, the small pump is allowed to start, and the standby interlock of the large and small pumps is engaged. Then, the circulating water return valves on both sides of the condenser are opened simultaneously. When the pressure of the outlet header of the large pump and the small pump drops to the interlock value or the opening of the two circulating water return valves is 100%, the small pump is started. After the small pump operates normally for 60 seconds, the two circulating water return valves are closed simultaneously. When the pressure of the outlet header rises to 0.22 MPa, the outlet valve of the large pump is closed to 70% opening. After waiting for 10 seconds, the two circulating water return valves are closed simultaneously. When the pressure of the outlet header rises to 0.22 MPa again, the outlet valve of the large pump is closed to 40% opening. After waiting for 10 seconds, the two circulating water return valves are closed simultaneously. When the pressure of the outlet header rises to 0.22 MPa again, the large pump is shut down. After waiting for 10 seconds, the two circulating water return valves are closed to 15% opening. When the large pump is switched to the simultaneous operation of the large pump and the small pump, firstly, it is determined that the large pump is operating normally, the small pump is allowed to start, and the standby interlock of the large pump and the small pump is engaged. Then, the two circulating water return valves are opened simultaneously. When the pressure of the outlet header pipe drops to the interlock value or the opening degree of the two circulating water return valves is 100%, the small pump is started and operates normally. At the same time, the two circulating water return valves are opened to 100%.

[0006] Preferably, the circulating water system includes three operating modes: operation of the large pump, operation of the small pump, and simultaneous operation of the large pump and the small pump.

[0007] Compared with existing technologies, the beneficial effects of this invention are that it realizes automatic sequential control of the switching of circulating water operation modes at the system level, which greatly simplifies the operation process, reduces the number of operation items, and reduces the workload of operation personnel; by replacing human subjective judgment and manual operation with automatic control technology, it has significant advantages of rapid and accurate response and reliable and stable operation, effectively avoiding operational risks; while improving the level of automation, it eliminates the safety hazards caused by frequent and large-scale operations at the source, laying a good foundation for the long-term stable operation of the unit. It should be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of the present invention, nor is it intended to restrict the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0008] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure for automatic switching of the operation mode of a circulating water system.

[0009] Numbering on the map: 12. Large pump; 13. Small pump; 14. Condenser; 15. Outlet header; 16. Small pump outlet valve; 17. Large pump outlet valve; 41. Circulating water return valve. Detailed Implementation

[0010] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0011] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0012] Please refer to Figure 1 The present invention provides a modular logic setting for automatic switching of the operation mode of a circulating water system, comprising the following steps: wherein, When switching from large pump 12 to small pump 13, firstly, it is determined that large pump 12 is operating normally, small pump 13 is allowed to start, and the standby interlock of large pump 12 and small pump 13 is engaged. Then, the circulating water return valves 41 located on both sides of the condenser 14 are opened simultaneously. When the pressure of the outlet header 15 of large pump 12 and small pump 13 drops to the interlock value or the opening degree of the two circulating water return valves 41 is 100%, small pump 13 is started. After small pump 13 operates normally for 60 seconds, the two circulating water return valves 41 are closed simultaneously. When the pressure of the outlet header 15 drops to the interlock value or the opening degree of the two circulating water return valves 41 is 100%, small pump 13 is started. When the pressure rises to 0.22 MPa, close the main pump outlet valve 17 to 70% opening. After waiting 10 seconds, simultaneously close both circulating water return valves 41. When the pressure of the outlet header 15 rises to 0.22 MPa again, close the main pump outlet valve 17 to 40% opening. After waiting 10 seconds, simultaneously close both circulating water return valves 41. When the pressure of the outlet header 15 rises to 0.22 MPa again, stop the main pump 12. After waiting 10 seconds, simultaneously close both circulating water return valves 41 to 15% opening.

[0013] In a preferred embodiment, such as Figure 1 As shown, when the large pump 12 is switched to the simultaneous operation of the large pump 12 and the small pump 13, firstly, it is determined that the large pump 12 is operating normally, the small pump 13 is allowed to start, and the standby interlock of the large pump 12 and the small pump 13 is engaged. Then, the two circulating water return valves 41 are opened simultaneously. When the pressure of the outlet header 15 drops to the interlock value or the opening degree of the two circulating water return valves 41 is 100%, the small pump 13 is started and operates normally. At the same time, the two circulating water return valves 41 are opened to 100%.

[0014] In a preferred embodiment, such as Figure 1 As shown, when switching from small pump 13 to large pump 12, firstly, it is determined that small pump 13 is operating normally, large pump 12 is allowed to start, and the standby interlock of large pump 12 and small pump 13 is engaged. Then, the circulating water return valves 41 located on both sides of the condenser 14 are opened simultaneously. When the pressure of the outlet header 15 of large pump 12 and small pump 13 drops to the interlock value or the opening degree of the two circulating water return valves 41 is 100%, large pump 12 is started. After large pump 12 operates normally for 60 seconds, the two circulating water return valves 41 are closed simultaneously. When the pressure of the outlet header 15 drops to the interlock value or the opening degree of the two circulating water return valves 41 is 100%, large pump 12 is started. After large pump 12 operates normally for 60 seconds, the two circulating water return valves 41 are closed simultaneously. When the pressure rises to 0.22 MPa, close the small pump outlet valve 16 to 70% opening. After waiting 10 seconds, simultaneously close both circulating water return valves 41. When the pressure of the outlet header 15 rises to 0.22 MPa again, close the small pump outlet valve 16 to 40% opening. After waiting 10 seconds, simultaneously close both circulating water return valves 41. When the pressure of the outlet header 15 rises to 0.22 MPa again, stop the small pump 13. After waiting 10 seconds, simultaneously close both circulating water return valves 41 to 30% opening.

[0015] In a preferred embodiment, such as Figure 1 As shown, when switching from large pump 12 and small pump 13 to large pump 12, firstly, it is determined that large pump 12 and small pump 13 are operating normally at the same time. Then, both circulating water return valves 41 are closed simultaneously. When the pressure of the outlet header 15 rises to 0.22 MPa, the outlet valve 16 of the small pump is closed to 70% opening. After waiting for 10 seconds, both circulating water return valves 41 are closed simultaneously. When the pressure of the outlet header 15 rises to 0.22 MPa again, the outlet valve 16 of the small pump is closed to 40% opening. After waiting for 10 seconds, both circulating water return valves 41 are closed simultaneously. When the pressure of the outlet header 15 rises to 0.22 MPa again, small pump 13 is stopped, and both circulating water return valves 41 are closed to 30% opening.

[0016] In a preferred embodiment, such as Figure 1 As shown, when the small pump 13 is switched to the large pump 12 and the small pump 13 is running simultaneously, firstly, it is determined that the small pump 13 is running normally, the large pump 12 is allowed to start, and the standby interlock of the large pump 12 and the small pump 13 is engaged. Then, the two circulating water return valves 41 are opened simultaneously. When the pressure of the outlet header 15 drops to the interlock value or the opening degree of the two circulating water return valves 41 is 100%, the large pump 12 is started and runs normally. At the same time, the two circulating water return valves 41 are opened to 100%.

[0017] In a preferred embodiment, such as Figure 1As shown, when switching from large pump 12 and small pump 13 to small pump 13, firstly, it is determined that large pump 12 and small pump 13 are operating normally at the same time. Then, both circulating water return valves 41 are closed simultaneously. When the pressure of the outlet header 15 rises to 0.22 MPa, the outlet valve 17 of the large pump is closed to 70% opening. After waiting for 10 seconds, both circulating water return valves 41 are closed simultaneously. When the pressure of the outlet header 15 rises to 0.22 MPa again, the outlet valve 17 of the large pump is closed to 40% opening. After waiting for 10 seconds, both circulating water return valves 41 are closed simultaneously. When the pressure of the outlet header 15 rises to 0.22 MPa again, large pump 12 is stopped, and both circulating water return valves 41 are closed to 15% opening.

[0018] In the description of this specification, the terms "connection," "installation," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0019] In the description of this specification, the terms "one embodiment," "some embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0020] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A modular logic operation method for automatic switching of a circulating water system, characterized in that, Includes the following steps: where, When switching from the large pump to the small pump, firstly, it is determined that the large pump is operating normally, the small pump is allowed to start, and the standby interlock of the large and small pumps is engaged. Then, the circulating water return valves on both sides of the condenser are opened simultaneously. When the pressure of the outlet header of the large pump and the small pump drops to the interlock value or the opening of the two circulating water return valves is 100%, the small pump is started. After the small pump operates normally for 60 seconds, the two circulating water return valves are closed simultaneously. When the pressure of the outlet header rises to 0.22 MPa, the outlet valve of the large pump is closed to 70% opening. After waiting for 10 seconds, the two circulating water return valves are closed simultaneously. When the pressure of the outlet header rises to 0.22 MPa again, the outlet valve of the large pump is closed to 40% opening. After waiting for 10 seconds, the two circulating water return valves are closed simultaneously. When the pressure of the outlet header rises to 0.22 MPa again, the large pump is shut down. After waiting for 10 seconds, the two circulating water return valves are closed to 15% opening. When the large pump is switched to the simultaneous operation of the large pump and the small pump, firstly, it is determined that the large pump is operating normally, the small pump is allowed to start, and the standby interlock of the large pump and the small pump is engaged. Then, the two circulating water return valves are opened simultaneously. When the pressure of the outlet header pipe drops to the interlock value or the opening degree of the two circulating water return valves is 100%, the small pump is started and operates normally. At the same time, the two circulating water return valves are opened to 100%.

2. The modular logic operation method for automatic switching of a circulating water system according to claim 1, characterized in that, The circulating water system includes three operating modes: operation of the large pump, operation of the small pump, and simultaneous operation of the large pump and the small pump.

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