Vacuum pump double-cooling water source system for thermal power plant in hot area

Abstract

The invention relates to the technical field of auxiliary engine systems of thermal power plants, aims to solve the problems of influence on performance, energy consumption and the like of a vacuum pump due to temperature rise of boiled cooling water when the environment air temperature is relatively high in the prior art, and provides a double-cooling water source system for a vacuum pump of a thermal power plant in a hot region, which comprises a boiled cooling water supply pipeline and a chilled water supply pipeline connected in parallel, the water supply pipelines and the water return pipelines are connected into a water supply main pipe connected with an inlet of the vacuum pump set, an outlet of the vacuum pump set is connected with a water return main pipe, the water return main pipe is connected with a cold water return pipeline and a chilled water return pipeline, and control valves are arranged on the water supply pipelines and the water return pipelines; the open cold water supply pipeline and the open cold water return pipeline are connected with the open circulating cooling water system, and the chilled water supply pipeline and the chilled water return pipeline are connected with the chilled water supply station; the cold water supply pipeline and the outlet end of each vacuum pump in the vacuum pump group are provided with temperature measuring points, and each temperature measuring point is provided with a temperature measuring device; it can be guaranteed that the vacuum pump normally and efficiently operates under the high-temperature environment working condition in a hot area.

Description

Technical Field

[0001] This invention relates to the field of auxiliary equipment systems for thermal power plants, and more specifically, to a dual cooling water source system for vacuum pumps in thermal power plants in hot regions. Background Technology

[0002] Vacuum pumps are important equipment used to establish and maintain vacuum in the condenser of thermal power plants. Common vacuum pumps include water ring vacuum pumps and Roots liquid ring vacuum pump sets. To reduce power consumption during normal operation of thermal power units, the vacuum system usually adopts a combination of water ring vacuum pump and Roots liquid ring pump.

[0003] In existing technologies, vacuum pumps typically use open-loop cooling water (hereinafter referred to as open-loop cooling water). In hot regions with high ambient temperatures (such as 37°C and above), the temperature of the open-loop cooling water rises accordingly, leading to poorer vacuum performance, increased energy consumption, and reduced reliability of the pump. In severe cases, it may fail to meet the system's vacuum requirements (such as a decrease in condenser vacuum) and even damage the equipment. Therefore, it is necessary to provide vacuum pumps with cooler cooling water and makeup water at lower temperatures in hot environments. Summary of the Invention

[0004] The present invention aims to provide a dual cooling water source system for vacuum pumps in thermal power plants in hot regions, in order to solve the problem that in the prior art, the cooling water of vacuum pumps uses open-loop cooling water. When the ambient temperature is high, the water temperature of the open-loop cooling water rises accordingly, which leads to poor vacuum performance, increased energy consumption, and reduced reliability of the pump. In severe cases, it may fail to meet the system's vacuum requirements or even damage the equipment.

[0005] This invention is achieved using the following technical solution: This invention provides a dual cooling water source system for vacuum pumps in thermal power plants in hot regions, including a cold water supply pipeline and a chilled water supply pipeline; One end of the open cooling water supply pipeline is connected to the open circulating cooling water system, and one end of the chilled water supply pipeline is connected to the chilled water supply station. The other end of both the cold water supply pipeline and the chilled water supply pipeline is connected to the cooling water supply main pipe. The cooling water supply header is connected to the inlet end of the vacuum pump unit, and the outlet end of the vacuum pump unit is connected to the cooling water return header. The cooling water return header is connected to the open cooling water return pipeline and the chilled water return pipeline, respectively; The open-loop cooling water return pipeline is connected to the open-loop cooling water system, and the chilled water return pipeline is connected to the chilled water supply station; Control valves are installed on the cold water supply pipeline, the chilled water supply pipeline, the cold water return pipeline, and the chilled water return pipeline; A cooling water supply temperature measuring point is installed on the cooling water supply pipeline, and a vacuum pump cooling water outlet temperature measuring point is installed at the outlet end of each vacuum pump in the vacuum pump group. Temperature measuring devices are installed at both the cooling water supply temperature measuring point and the vacuum pump cooling water outlet temperature measuring point.

[0006] As a preferred technical solution: Both the control valve and the temperature measuring device are connected to the control system.

[0007] As a preferred technical solution: A cold water supply control valve is installed on the cold water supply pipeline, and a chilled water supply control valve is installed on the chilled water supply pipeline.

[0008] As a preferred technical solution: A cold water return control valve is installed on the cold water return pipeline, and a chilled water return control valve is installed on the chilled water return pipeline.

[0009] As a preferred technical solution: The temperature measuring device, the cold water supply control valve, the chilled water supply control valve, the cold water return control valve, and the chilled water return control valve are all connected to the control system.

[0010] As a preferred technical solution: The chilled water supply station includes an air-cooled screw chiller and a chilled water circulation pump. The chilled water supply pipeline is connected to the air-cooled screw chiller, the chilled water return pipeline is connected to the chilled water circulation pump, and the chilled water circulation pump is connected to the air-cooled screw chiller.

[0011] As a preferred technical solution: The chilled water supply station also includes an expansion water replenishment and pressure regulating unit, which is connected to the inlet of the chilled water circulation pump.

[0012] As a preferred technical solution: A control valve is installed between the expansion water replenishment pressure unit and the cold water circulation pump.

[0013] As a preferred technical solution: The expansion water replenishment and constant pressure unit is connected to the condensate water replenishment system.

[0014] As a preferred technical solution: The vacuum pump set includes a Roots liquid ring vacuum pump and a water ring vacuum pump.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This invention provides a switchable low-temperature water source, namely chilled water, for the vacuum pumps in thermal power plants by setting up open cooling water supply pipelines and chilled water supply pipelines. The open cooling water supply pipeline is connected to the vacuum pump group and the open circulating cooling water system, and the chilled water supply pipeline is connected to the vacuum pump group and the chilled water supply station. Control valves are installed on the two supply and return water pipelines. The chilled water and the open circulating cooling water together constitute the dual cooling water source of the vacuum pump, ensuring that the internal working fluid water of water ring vacuum pumps or Roots liquid ring vacuum pumps in thermal power plants in hot regions is kept at a low temperature in high-temperature environments. This ensures that the vacuum pump can still obtain low-temperature cooling water and operate normally and efficiently in high-temperature environments in hot regions, and ensures the vacuum pump's ability to establish maximum vacuum and its stable and efficient operation.

[0016] 2. This invention uses an air-cooled screw chiller unit to cool and lower the temperature of chilled water, providing a continuous and efficient supply of chilled water. It offers advantages such as flexible installation, convenient operation and maintenance, and adaptability to various cooling needs. The air-cooled screw chiller unit has a high degree of integration, requiring only connection to chilled water piping and power for immediate use. The installation and commissioning process is simple, allowing for rapid response to temporary or emergency cooling needs. It has low dependence on water sources, as the condensation heat of the chiller unit is directly dissipated into the atmosphere through air cooling, completing the heat dissipation stage of the refrigeration cycle, offering significant advantages in water-scarce areas. The screw compressor has a mature and reliable structure, stable operation, and lower maintenance costs compared to other types of units such as piston chillers. It can operate stably within a wide range of ambient temperatures, adapting to different climatic environments.

[0017] 3. The air-cooled screw chiller unit of the present invention, together with the chilled water circulation pump and the expansion water replenishment pressure unit, can ensure a stable circulating supply of chilled water. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the dual cooling water source system for vacuum pumps in thermal power plants in hot regions, as described in this invention.

[0019] Icons: 1-Open chilled water supply pipeline, 2-Chilled water supply pipeline, 3-Cooling water supply main pipe, 4-Open chilled water supply control valve, 5-Chilled water supply control valve, 6-Open chilled water supply temperature measuring point, 7-Open chilled water return pipeline, 8-Chilled water return pipeline, 9-Cooling water return main pipe, 10-Open chilled water return control valve, 11-Chilled water return control valve, 12-Vacuum pump cooling water outlet temperature measuring point, 13-Vacuum pump unit, 14-Air-cooled screw chiller unit, 15-Chilled water circulation pump, 16-Expansion water replenishment constant pressure unit. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 like Figure 1 As shown, this embodiment proposes a dual cooling water source system for vacuum pumps in thermal power plants in hot regions, including a chilled water supply pipeline 1 and a chilled water supply pipeline 2; One end of the open cooling water supply pipeline 1 is connected to the open circulating cooling water system, which is used to provide open circulating cooling water. One end of the chilled water supply pipeline 2 is connected to the chilled water supply station, which is used to provide chilled water (the temperature of the chilled water is lower than that of the open-loop cooling water). The other ends of both the cold water supply pipeline 1 and the chilled water supply pipeline 2 are connected to the cooling water supply main pipe 3. Therefore, the cold water supply pipeline 1 and the chilled water supply pipeline 2 are connected in parallel.

[0022] Preferably, the cold water supply pipeline 1 and the chilled water supply pipeline 2 are connected to the cooling water supply main pipeline 3 at a suitable location, such as near the boundary of the main plant.

[0023] The cold water supply pipeline 1 is equipped with a cold water supply control valve 4, and the chilled water supply pipeline 2 is equipped with a chilled water supply control valve 5.

[0024] In this way, the open-loop cooling water and chilled water are controlled separately through corresponding control valves. In hot regions and high-temperature environments, the water source can be switched from open cooling water to relatively low-temperature chilled water through the control valves. This avoids affecting the vacuum performance of the vacuum pump, avoids increased energy consumption, ensures the reliability of the vacuum pump, meets the system's vacuum requirements, and protects the equipment.

[0025] The cooling water supply header 3 is connected to the inlet end of the vacuum pump group 13, and the outlet end of the vacuum pump group 13 is connected to the cooling water return header 9. One end of the cooling water return header 9 is connected to the outlet end of the vacuum pump group 13, and the other end of the cooling water return header 9 is connected to the open cooling water return pipe 7 and the chilled water return pipe 8 respectively.

[0026] Preferably, the cooling water return main pipe 9 is connected to the open cooling water return pipe 7 and the chilled water return pipe 8 at a suitable location, such as near the boundary of the main plant.

[0027] The open cooling water return pipe 7 is connected to the open circulating cooling water system; The chilled water return pipeline 8 is connected to the chilled water supply station.

[0028] The chilled water return pipeline 7 is equipped with a chilled water return control valve 10, and the chilled water return pipeline 8 is equipped with a chilled water return control valve 11.

[0029] In this way, the open-loop cooling water and chilled water can be returned separately, so that the open-loop cooling water and chilled water return to the open-loop cooling water system and the chilled water supply station respectively.

[0030] The open cooling water supply pipeline 1 is equipped with an open cooling water supply temperature measuring point 6, and a temperature measuring device is installed at the open cooling water supply temperature measuring point 6. The temperature measuring device is used to measure the temperature of the open circulating cooling water.

[0031] The vacuum pump assembly 13 is provided with a vacuum pump cooling water outlet temperature measuring point 12 at its outlet end. A temperature measuring device is installed at the vacuum pump cooling water outlet temperature measuring point 12 to measure the temperature of the vacuum pump outlet cooling water.

[0032] Preferably, each vacuum pump in the vacuum pump group 13 is provided with a vacuum pump cooling water outlet temperature measuring point 12 at its outlet end, and a temperature measuring device is installed thereon.

[0033] When the temperature measuring device detects that the supply temperature of the open-loop cooling water or the temperature of the cooling water at the vacuum pump outlet exceeds the set temperature, the open-loop cooling water supply control valve 4 and the open-loop cooling water return control valve 10 are closed, and the chilled water supply control valve 5 and the chilled water return control valve 11 are opened to switch the low-temperature water source (i.e., chilled water) for the vacuum pump of the thermal power plant.

[0034] Preferably, the temperature measuring device, the open-circulation cooling water supply control valve 4, the chilled water supply control valve 5, the open-circulation cooling water return control valve 10, and the chilled water return control valve 11 are all connected to the control system. The temperature measuring device transmits the collected supply temperature of the open-circulation cooling water or the temperature signal of the cooling water at the vacuum pump outlet to the control system. When the supply temperature of the open-circulation cooling water or the temperature of the cooling water at the vacuum pump outlet exceeds the set temperature, the control system interlocks and controls the open-circulation cooling water supply control valve 4 and the open-circulation cooling water return control valve 10 to close, and controls the chilled water supply control valve 5 and the chilled water return control valve 11 to open, switching the water source to chilled water and causing the return water to flow back to the chilled water supply station.

[0035] Thus, by setting up a control system and interlocking the temperature measuring device with the control valve, intelligent and automated control is achieved. The valve status can be automatically adjusted according to the real-time changes in cooling water temperature to ensure that the working fluid temperature of the vacuum pump remains constant within the optimal range, overcoming the problem of lag in manual adjustment. This effectively prevents problems such as decreased vacuum pump performance and increased energy consumption caused by excessively high water temperature, ensuring the stable operation of the vacuum pump unit 13.

[0036] Preferably, the chilled water supply station includes an air-cooled screw chiller unit 14 and a chilled water circulation pump 15. The chilled water supply pipeline 2 is connected to the air-cooled screw chiller unit 14, the chilled water return pipeline 8 is connected to the chilled water circulation pump 15, and the chilled water circulation pump 15 is connected to the air-cooled screw chiller unit 14. The chilled water circulation pump 15 is used to drive the chilled water circulation flow.

[0037] Thus, the chilled water cooled by the air-cooled screw chiller 14 can enter the vacuum pump group 13 through the chilled water supply pipeline 2 and the cooling water supply header 3. After passing through the vacuum pump group 13, it returns to the chilled water supply station through the cooling water return header 9 and the chilled water return pipeline 8, and is cooled again by the air-cooled screw chiller 14.

[0038] The chilled water circulation pump 15 can pump the chilled water that has undergone heat exchange in the vacuum pump group 13 back to the air-cooled screw chiller 14. The chilled water is then cooled back to a low operating temperature in the air-cooled screw chiller 14 and then sent back to the vacuum pump group 13 to complete the circulation.

[0039] Preferably, the chilled water supply station further includes an expansion water replenishment and pressure regulating unit 16, which is connected to the inlet of the chilled water circulation pump 15. The expansion water replenishment and pressure regulating unit 16 can maintain the pressure stability of the entire chilled water supply and return system under temperature fluctuations, adapt to volume expansion, and replenish water to the system.

[0040] Preferably, a control valve is provided between the expansion water replenishment pressure unit 16 and the cold water circulation pump 15.

[0041] Preferably, the expansion water replenishment pressure unit 16 is connected to the condensate water replenishment system, which is used to provide replenishment water.

[0042] Preferably, multiple sets of the air-cooled screw chiller unit 14 and the chilled water circulation pump 15 can be set as needed.

[0043] Preferably, the temperature measuring device may, but is not limited to, employ a temperature sensor.

[0044] Preferably, the control valve in this embodiment can be an electrically controlled valve.

[0045] Preferably, the vacuum pump assembly 13 includes a Roots liquid ring vacuum pump and a water ring vacuum pump, specifically including a working fluid cooler for Roots liquid ring vacuum pump A, a heat exchanger cooler for Roots liquid ring vacuum pump B, a cooler for water ring vacuum pump A, and a cooler for water ring vacuum pump B.

[0046] The cooling water supply main pipe 3 is connected to the vacuum pump group 13 at one end, which is divided into multiple water supply branches. Each water supply branch is connected to a vacuum pump and supplies water to each vacuum pump.

[0047] The cooling water return main pipe 9 is connected to the vacuum pump group 13 at one end, which is divided into multiple return water branches. Each of the return water branches is connected to each vacuum pump and collects the return water from each vacuum pump.

[0048] This invention connects the open cooling water supply pipeline 1 to the vacuum pump unit 13 and the open circulating cooling water system by setting up an open cooling water supply pipeline 2, and the chilled water supply pipeline 2 to the vacuum pump unit 13 and the chilled water supply station. Control valves are installed on the two supply and return water pipelines to provide a switchable low-temperature water source, namely chilled water, for the vacuum pump of the thermal power plant. The chilled water and the open circulating cooling water together constitute the dual cooling water source of the vacuum pump, ensuring that the internal working fluid water of water ring vacuum pumps or Roots liquid ring vacuum pumps in thermal power plants in hot regions is kept at a low temperature in high-temperature environments. This ensures that the vacuum pump can still obtain low-temperature cooling water and operate normally and efficiently in high-temperature environments in hot regions, and ensures the vacuum pump's ability to establish maximum vacuum and its stable and efficient operation.

[0049] This invention utilizes an air-cooled screw chiller unit 14 to cool and lower the temperature of chilled water, providing a continuous and efficient supply of chilled water. It offers advantages such as flexible installation, convenient operation and maintenance, and adaptability to various cooling scenarios. The air-cooled screw chiller unit 14 has a high degree of integration, requiring only connection to chilled water piping and power for immediate use. The installation and commissioning process is simple, allowing for rapid response to temporary or emergency cooling needs. It has low dependence on water sources, as the condensation heat of the chiller unit is directly dissipated into the atmosphere through air cooling, completing the heat dissipation stage of the refrigeration cycle, offering significant advantages in water-scarce regions. The screw compressor has a mature and reliable structure, stable operation, and lower maintenance costs compared to other types of units such as piston compressors. It can operate stably within a wide range of ambient temperatures, adapting to different climatic environments.

[0050] The air-cooled screw chiller unit 14 of the present invention, together with the chilled water circulation pump 15 (frequency conversion) and the expansion water replenishment constant pressure unit 16, can ensure a stable circulating supply of chilled water.

[0051] The air-cooled screw chiller 14, chilled water circulating pump 15, expansion water replenishment and constant pressure unit 16, and condensate replenishment system in this invention can be existing products.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dual cooling water source system for vacuum pumps in thermal power plants in hot regions, characterized in that: This includes opening cold water supply lines and chilled water supply lines; One end of the open cooling water supply pipeline is connected to the open circulating cooling water system, and one end of the chilled water supply pipeline is connected to the chilled water supply station. The other end of both the cold water supply pipeline and the chilled water supply pipeline is connected to the cooling water supply main pipe. The cooling water supply header is connected to the inlet end of the vacuum pump unit, and the outlet end of the vacuum pump unit is connected to the cooling water return header. The cooling water return header is connected to the open cooling water return pipeline and the chilled water return pipeline, respectively; The open-loop cooling water return pipeline is connected to the open-loop cooling water system, and the chilled water return pipeline is connected to the chilled water supply station; Control valves are installed on the cold water supply pipeline, the chilled water supply pipeline, the cold water return pipeline, and the chilled water return pipeline; A cooling water supply temperature measuring point is installed on the cooling water supply pipeline, and a vacuum pump cooling water outlet temperature measuring point is installed at the outlet end of each vacuum pump in the vacuum pump group. Temperature measuring devices are installed at both the cooling water supply temperature measuring point and the vacuum pump cooling water outlet temperature measuring point.

2. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to claim 1, characterized in that: Both the control valve and the temperature measuring device are connected to the control system.

3. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to claim 2, characterized in that: A cold water supply control valve is installed on the cold water supply pipeline, and a chilled water supply control valve is installed on the chilled water supply pipeline.

4. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to claim 3, characterized in that: A cold water return control valve is installed on the cold water return pipeline, and a chilled water return control valve is installed on the chilled water return pipeline.

5. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to claim 4, characterized in that: The temperature measuring device, the cold water supply control valve, the chilled water supply control valve, the cold water return control valve, and the chilled water return control valve are all connected to the control system.

6. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to claim 1, characterized in that: The chilled water supply station includes an air-cooled screw chiller and a chilled water circulation pump. The chilled water supply pipeline is connected to the air-cooled screw chiller, the chilled water return pipeline is connected to the chilled water circulation pump, and the chilled water circulation pump is connected to the air-cooled screw chiller.

7. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to claim 6, characterized in that: The chilled water supply station also includes an expansion water replenishment and pressure regulating unit, which is connected to the inlet of the chilled water circulation pump.

8. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to claim 7, characterized in that: A control valve is installed between the expansion water replenishment pressure unit and the cold water circulation pump.

9. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to claim 7, characterized in that: The expansion water replenishment and constant pressure unit is connected to the condensate water replenishment system.

10. The dual cooling water source system for vacuum pumps in thermal power plants in hot regions according to any one of claims 1-9, characterized in that: The vacuum pump set includes a Roots liquid ring vacuum pump and a water ring vacuum pump.

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