Novel switching device shared by two machines of closed water system

Abstract

A novel switching device shared by two machines of a closed water system relates to the technical field of closed water systems of steam turbine sets of thermal power plants, and comprises two closed water systems of units, a valve assembly and an air compressor room water path, and each closed water system of the units is provided with two closed pumps. The two unit closed type water systems are connected in series through a closed type water main pipe water inlet communication door and a closed type water main pipe water return communication door, the valve assembly is installed at the position of the closed type water main pipe water inlet communication door and the position of the closed type water main pipe water return communication door, and a hydrocyclone is installed at the junction of closed type water main pipes. The air compressor room water path comprises a cooling water inlet pipe and a cooling water return pipe which are respectively communicated with the two unit closed water systems; according to the scheme, efficient sharing and flexible switching of the two-machine closed water system are achieved, energy consumption is reduced, and the operation stability of equipment and the adaptability of the system are improved.

Description

Technical Field

[0001] This utility model relates to the technical field of closed-loop water systems for steam turbine units in thermal power plants, specifically a novel closed-loop water system switching device shared by two turbine units. Background Technology

[0002] The closed-loop water system of a steam turbine unit is a relatively independent circulating water system, mainly composed of a closed-loop cooling water pump, a closed-loop water heat exchanger, an expansion tank, filters, and related pipes and valves. This system uses demineralized water as the medium, which is pumped by the closed-loop cooling water pump to various devices requiring cooling, such as the steam turbine's lubricating oil cooler, the generator's air cooler, and the hydrogen cooler, removing the heat generated during equipment operation. The hot water then returns to the closed-loop water heat exchanger, where it exchanges heat with the open-loop circulating water. The cooled water then re-enters the circulation, thus forming a closed-loop cycle.

[0003] For example, the Chinese authorized patent CN215832270U, ​​entitled "A Closed-Loop Circulating Cooling Water System," includes a closed-loop water expansion tank and a closed-loop circulating cooling water circuit connected to the water expansion tank. The closed-loop circulating cooling water circuit includes a water supply header connected to the closed-loop water expansion tank, which sequentially connects to a closed-loop pump assembly, a closed-loop water cooler assembly, multiple parallel cooling equipment pipelines, and a return header connecting the cooling equipment pipelines and the closed-loop pump assembly. The closed-loop water expansion tank is equipped with at least two independent liquid level monitoring devices, each connected to a remote monitoring system. This invention improves the reliability of liquid level monitoring and ensures the normal operation of the unit by setting multiple independent liquid level detection devices.

[0004] However, existing technologies typically involve each unit operating independently, equipped with its own closed-loop pump and related circulation pipelines. This operating mode suffers from significant energy losses. When a unit is operating at partial load or when one unit is shut down for maintenance, the closed-loop pumps still need to operate at rated power, resulting in wasted plant power. Simultaneously, the closed-loop water circulation is not efficient enough, leading to water resource waste. Furthermore, it lacks reliability and flexibility; when one unit fails, the resources of the other unit cannot be efficiently utilized, failing to meet the requirements of modern thermal power generation for energy conservation, stability, and flexible operation. Therefore, it does not meet current needs. To address this, we propose a novel closed-loop water system dual-unit shared switching device. Utility Model Content

[0005] The purpose of this invention is to provide a novel closed-loop water system dual-machine switching device to solve the problems of high energy consumption, low equipment reliability, and insufficient flexibility in existing closed-loop water systems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a novel closed-loop water system switching device for two units, comprising two closed-loop water systems, valve assemblies, and a compressor room water circuit. Each unit's closed-loop water system is equipped with two closed-loop pumps, and the two closed-loop pumps are connected to their respective unit's closed-loop water users via pipelines. The two unit's closed-loop water systems are connected in series via a closed-loop water header inlet connection valve and a closed-loop water header return connection valve. The valve assemblies are installed at the closed-loop water header inlet connection valve and the closed-loop water header return connection valve, and a cyclone separator is installed at the confluence of the closed-loop water headers. The compressor room water circuit includes cooling water inlet and return pipes, which are respectively connected to the two unit's closed-loop water systems. Each unit's connecting pipeline is equipped with independent supply and return water valves.

[0007] Preferably, the valve assembly includes a main interlock valve, a flow balancing valve, and a check valve, which are sequentially arranged on the closed-loop manhole inlet and outlet manholes. The main interlock valve is a pressure-triggered quick-opening structure, the flow balancing valve is a V-type ball valve and is connected to an electric actuator, and the check valve is equipped with a buffer structure to prevent water hammer impact.

[0008] Preferably, the main interlock valve includes an interface for receiving pressure signals, and the main interlock valve changes its opening and closing state according to the pressure signals.

[0009] Preferably, the V-type ball valve of the flow balancing valve is connected to an electric actuator, and the electric actuator drives the V-type ball valve to adjust the flow rate.

[0010] Preferably, the check valve has a buffer mechanism inside, and the water flow impacts the buffer component to generate deformation in order to buffer the water hammer impact force.

[0011] Preferably, the hydrocyclone is a spiral guide, including a guide tube and spiral blades disposed inside the guide tube. The guide tube is installed at the confluence of the closed jellyfish tube, and the spiral blades extend spirally along the inner wall of the guide tube.

[0012] Preferably, the supply and return water valves on each unit side are pneumatic valves.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. This utility model reduces the operating time and number of closed-loop pumps by having two units share one closed-loop pump, directly lowering plant power consumption. When one unit is shut down, the closed-loop water from the operating unit can be introduced into the system of the shut-down unit to establish circulation, avoiding waste of closed-loop water, improving water resource utilization efficiency, and achieving energy conservation.

[0015] 2. The two units of this utility model can be freely switched between closed-loop water systems. When one unit malfunctions or needs maintenance, the operating mode can be quickly adjusted so that the other unit can take over all the cooling tasks, thus ensuring the continuity of production.

[0016] 3. The valve assembly and cyclone separator of this utility model work together to ensure the stability of system pressure and flow. The main interlock valve responds quickly to changes in system pressure, the flow balancing valve precisely regulates the flow, the check valve prevents water hammer, and the cyclone pressure stabilizing device eliminates pressure differences between units. These measures reduce frequent start-ups and shutdowns and unnecessary operating losses, extend the service life of closed-loop pumps, valves, and other equipment, improve the reliability and stability of the entire closed-loop water system, and provide a strong guarantee for the safe and stable operation of the unit. Attached Figure Description

[0017] Figure 1 This is a diagram of the closed-loop water system of this utility model, which uses a shared switching system for two machines.

[0018] In the diagram: 1. Closed-loop sluice gate inlet valve; 2. Closed-loop sluice gate return valve; 3. Closed-loop pump; 4. Main interlock valve; 5. Flow balancing valve; 6. Check valve; 7. Cyclone separator. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0020] Please see Figure 1 This utility model provides an embodiment of a novel closed-loop water system dual-unit switching device, comprising two closed-loop water systems for two units, valve assemblies, and a water circuit for the air compressor room. Each unit's closed-loop water system is equipped with two closed-loop pumps 3, and the two closed-loop pumps 3 are connected to their respective unit's closed-loop water users via pipelines. The two unit closed-loop water systems are connected in series via a closed-loop water header inlet connecting valve 1 and a closed-loop water header return connecting valve 2. The valve assembly is installed at the closed-loop water header inlet connecting valve 1 and the closed-loop water header return connecting valve 2. There are two return water connection valves for the closed water supply pipe, and a hydrocyclone 7 is installed at the junction of the closed water supply pipe. The water circuit of the air compressor room includes cooling water inlet and return water pipes, which are connected to the closed water system of the two units respectively. Each unit side of the connecting pipe is equipped with independent supply and return water valves, and the supply and return water valves of each unit side are pneumatic valves, realizing the interconnection of the closed water systems of the two units, laying the foundation for the rational allocation and efficient utilization of resources, and effectively reducing the waste of closed water and unnecessary operating losses of equipment.

[0021] When both units are operating normally, the closed-loop pump of one unit is activated first. Taking the operation of closed-loop pump 3 of the first unit and the standby operation of closed-loop pump 3 of the second unit as an example, after the closed-loop water is pressurized by the closed-loop pump 3 of the first unit, a portion of the closed-loop water is supplied to the closed-loop water users of the first unit itself, and the other portion is transported to the second unit through the closed-loop water header connection valve to meet the closed-loop water users' needs of the second unit. During this process, the valve assembly at the closed-loop water header connection valve plays its role. The main interlock valve 4 remains open when the system pressure is stable to ensure normal flow of closed-loop water; the flow balancing valve 5, based on the system flow monitoring data, drives the V-type ball valve through an electric actuator to precisely adjust the opening degree, so that the closed-loop water flow distribution between the two units is balanced; the check valve 6 prevents water hammer impact and maintains system stability. At the same time, the air compressor room is supplied with closed-loop water by the operating unit, and the cooling water inlet and outlet valves of the air compressor room on the second unit side are closed to ensure reasonable circulation of closed-loop water.

[0022] The valve assembly includes a main interlock valve 4, a flow balancing valve 5, and a check valve 6, which are sequentially installed on the closed-loop manhole inlet connecting valve 1 and the closed-loop manhole return connecting valve 2. The main interlock valve 4 is a pressure-triggered quick-opening structure and includes an interface for receiving pressure signals. The main interlock valve 4 changes its opening and closing state according to the pressure signal. The flow balancing valve 5 is a V-type ball valve and is connected to an electric actuator. The V-type ball valve of the flow balancing valve 5 is connected to the electric actuator, and the electric actuator drives the V-type ball valve to adjust the flow. The check valve 6 is equipped with a buffer structure to prevent water hammer impact. The check valve 6 has a buffer mechanism inside, and the water flow impact buffer component deforms to buffer the water hammer impact force.

[0023] A hydrocyclone 7 is installed at the confluence of the closed-loop water supply pipes. The hydrocyclone 7 is a spiral guide, comprising a guide pipe and spiral blades installed within the guide pipe. The guide pipe is installed at the confluence of the closed-loop water supply pipes, and the spiral blades extend spirally along the inner wall of the guide pipe. When the closed-loop water flows at the confluence, the spiral blades cause the water flow to swirl. This swirling flow effectively eliminates pressure differences between different units, making the flow of closed-loop water within the system more stable and uniform, further improving the operating efficiency and reliability of the entire closed-loop water system. The hydrocyclone 7 optimizes the flow state of closed-loop water within the system, reduces water flow instability caused by pressure differences, and lowers the pressure fluctuations experienced by the equipment during operation.

[0024] Switching and Adjustment When One Unit is Shut Down: When the second unit shuts down and the first unit continues to run, first open the cooling water inlet and outlet valves of the air compressor room on the second unit side. At this time, the system pressure changes, and the pressure triggering mechanism of the main interlock valve 4 responds quickly, adjusting the opening degree according to the pressure signal to ensure stable system pressure. The flow balancing valve 5 is readjusted; according to the new flow demand, the electric actuator drives the V-type ball valve to change the opening degree, ensuring that the cooling water volume of both the operating and shut-down units meets the requirements. The check valve 6 prevents water hammer impact during the switching process, protecting system pipelines and equipment. At the same time, the closed-loop water from the operating unit enters the closed-loop water system of the shut-down unit through the connecting valve, establishing circulation and realizing full utilization of the closed-loop water to achieve energy saving and consumption reduction.

[0025] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A novel closed-loop water system switching device for two units, comprising a closed-loop water system for two units, valve assemblies, and a water circuit for the air compressor room, characterized in that: Each of the aforementioned units' closed-loop water systems is equipped with two closed-loop pumps (3), and the two closed-loop pumps (3) are connected to the closed-loop water users of their respective units through pipelines. The two units' closed-loop water systems are connected in series through a closed-loop water header inlet valve (1) and a closed-loop water header return valve (2). The valve assembly is installed at the closed-loop water header inlet valve (1) and the closed-loop water header return valve (2), and a hydrocyclone (7) is installed at the junction of the closed-loop water headers. The air compressor room water circuit includes cooling water inlet and return pipes, which are connected to the closed-loop water systems of the two units respectively. Each unit's connecting pipeline is equipped with independent supply and return valves.

2. The novel closed-loop water system dual-machine shared switching device according to claim 1, characterized in that: The valve assembly includes a main interlock valve (4), a flow balancing valve (5), and a check valve (6) sequentially installed on the closed-loop manhole inlet valve (1) and the closed-loop manhole return valve (2). The main interlock valve (4) is a pressure-triggered quick-opening structure. The flow balancing valve (5) is a V-type ball valve and is connected to an electric actuator. The check valve (6) is equipped with a buffer structure to prevent water hammer impact.

3. A novel closed-loop water system dual-machine shared switching device according to claim 2, characterized in that: The main interlock valve (4) includes an interface for receiving pressure signals, and the main interlock valve (4) changes its opening and closing state according to the pressure signals.

4. A novel closed-loop water system dual-machine shared switching device according to claim 2, characterized in that: The V-type ball valve of the flow balancing valve (5) is connected to the electric actuator, and the electric actuator drives the V-type ball valve to adjust the flow.

5. A novel closed-loop water system dual-machine shared switching device according to claim 2, characterized in that: The check valve (6) is equipped with a buffer mechanism inside. The water flow impacts the buffer component and causes deformation to buffer the water hammer impact force.

6. A novel closed-loop water system dual-machine shared switching device according to claim 1, characterized in that: The hydrocyclone (7) is a spiral guide, including a guide tube and spiral blades disposed in the guide tube. The guide tube is installed at the junction of the closed jellyfish tube, and the spiral blades extend spirally along the inner wall of the guide tube.

7. The novel closed-loop water system dual-machine shared switching device according to claim 1, characterized in that: The supply and return water valves on each unit side are pneumatic valves.

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