Low-additive hydrophobic pump seal cooling seal structure and system

Abstract

The application provides a low-pressure hydrophobic pump mechanical seal cooling sealing structure and system, and relates to the technical field of electric heating. The application comprises a hydrophobic pump and a condenser. The mechanical seal of the hydrophobic pump has a high-pressure side and a low-pressure side. The water inlets of the high-pressure side and the low-pressure side of the hydrophobic pump are connected with the water supplement pipelines of the condenser, respectively. The water supplement pipelines of the condenser are filled with desalted water. The water outlets of the high-pressure side and the low-pressure side of the hydrophobic pump are connected with the condenser, respectively. The water inlets of the high-pressure side and the low-pressure side of the hydrophobic pump are connected with the water supplement pipelines of the condenser, respectively. The water supplement pipelines of the condenser are filled with desalted water. The mechanical seal of the hydrophobic pump is cooled by the desalted water, which prevents the water used to cool the mechanical seal of the hydrophobic pump from entering the hydrophobic pump and polluting the hydrophobic water, and reduces the risk of fouling of the boiler tube wall and the turbine blade. The desalted water used to cool the mechanical seal has moderate temperature and pressure when entering the condenser, and the desalted water used to cool the mechanical seal can be recycled, which reduces the energy consumption and has strong applicability.

Description

Technical Field

[0001] This invention relates to the field of electrothermal technology, and in particular to a cooling and sealing structure and system for a low-pressure hydrophobic pump mechanical seal. Background Technology

[0002] During power generation at the power plant, some steam turbine generators are equipped with multiple sets of low-pressure heaters, which flow to the condenser in stages by gravity. In this process, to reduce heat consumption and improve heat recovery rate, intermediate stage condensate is pumped to the low-pressure heater stage via a low-pressure heater condensate pump. After being heated by the upper-stage low-pressure heater, it is sent to the condensate header and then enters the deaerator to make up water for the boiler.

[0003] Currently, there are two sealing methods for low-pressure heater condensate pumps: packing seals and mechanical seals. Due to their inherent limitations, packing seals have a shorter service life, so most low-pressure heater condensate pumps use mechanical seals. However, during the mechanical sealing process, industrial circulating water is often used for seal cooling, which can easily affect the water quality of the condensate system. This increases the risk of scaling on boiler tube walls and turbine blades, affecting the service life and operational stability of the boiler and turbine. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a cooling and sealing structure and system for a low-pressure condensate pump mechanical seal, which solves the problem that cooling the mechanical seal of the condensate pump in the prior art affects the water quality of the condensate system and increases the risk of scaling on the boiler tube walls and turbine blades.

[0005] To achieve the above and other related objectives, the present invention provides a cooling and sealing structure for a low-pressure condensate pump mechanical seal, comprising a condensate pump and a condenser. The mechanical seal of the condensate pump has a high-pressure side and a low-pressure side. The inlets of the high-pressure side and the low-pressure side of the condensate pump are respectively connected to the water supply pipe of the condenser. The water supply pipe of the condenser contains demineralized water. The outlets of the high-pressure side and the low-pressure side of the condensate pump are respectively connected to the condenser.

[0006] Optionally, a main water supply pipe and a branch water supply pipe are provided between the condenser's water supply pipe and the condensate pump. The main water supply pipe is connected to the condenser's water supply pipe, and the branch water supply pipe is connected to the high-pressure side and low-pressure side inlet of the condensate pump, respectively. A demineralized water supply main valve is provided on the main water supply pipe.

[0007] Optionally, the inlets of the high-pressure side and low-pressure side of the condensate pump are connected to the circulating water circuit through the water supply branch pipes, the circulating water circuit has a circulating water main pipe, the circulating water main pipe is connected to the water supply branch pipes, the circulating water main pipe is equipped with a circulating water supply main valve, the outlets of the high-pressure side and low-pressure side of the condensate pump are connected to the circulating water outlet, the circulating water outlet is equipped with a circulating water outlet main valve, and the circulating water is discharged from the low-pressure condensate pump mechanical seal cooling sealing structure through the circulating water outlet.

[0008] Optionally, a first control valve is provided at the inlet of the high-pressure side and the low-pressure side of the condensate pump, and a second control valve is provided at the outlet of the high-pressure side and the low-pressure side of the condensate pump.

[0009] Optionally, a main outlet pipe and branch outlet pipes are provided between the outlets of the high-pressure side and the low-pressure side of the condensate pump and the condenser. The branch outlet pipes are respectively connected to the high-pressure side and the low-pressure side of the condensate pump. The branch outlet pipes converge to form the main outlet pipe, which is connected to the condenser. A main outlet valve is provided on the main outlet pipe, which is close to the condensate pump. After the branch outlet pipes converge, they are also connected to the circulating water outlet.

[0010] Optionally, a shut-off valve is also provided on the main outlet pipe, and the shut-off valve is located near the condenser.

[0011] Optionally, both the main water supply pipe and the branch water supply pipes are made of stainless steel.

[0012] Optionally, both the main outlet pipe and the branch outlet pipes are made of stainless steel.

[0013] The present invention also provides a cooling and sealing system for a low-pressure condensate pump mechanical seal, including the cooling and sealing structure for a low-pressure condensate pump mechanical seal as described above.

[0014] As described above, the cooling and sealing structure and system for a low-pressure condensate pump mechanical seal of the present invention has the following beneficial effects: The inlets of the high-pressure and low-pressure sides of the condensate pump are connected to the condenser's makeup water pipes, respectively. The makeup water pipes in the condenser are demineralized water. Using demineralized water to cool the condensate pump mechanical seal prevents the water used to cool the mechanical seal from entering the condensate pump and contaminating the condensate, reducing the risk of scaling on the boiler tube walls and turbine blades. Furthermore, the demineralized water used to cool the mechanical seal enters the condenser at a suitable temperature and pressure, and can be recycled, resulting in low energy consumption and strong applicability. Attached Figure Description

[0015] Figure 1 The diagram shown is a structural schematic of the low-pressure hydrophobic pump mechanical seal cooling and sealing system according to an embodiment of the present invention.

[0016] Figure 2 Displayed as Figure 1 Enlarged diagram of point A in the middle.

[0017] Labeling Explanation: 1. Low-pressure heater No. 5; 2. Low-pressure heater No. 6; 3. Low-pressure heater No. 7; 4. Shaft seal heater; 5. Condenser; 6. Condensate pump; 7. Shut-off valve; 8. Main outlet pipe; 9. Main circulating water supply valve; 10. Main circulating water pipe; 11. Main supply pipe; 12. Main demineralized water supply valve; 13. First control valve; 14. Supply branch pipe; 15. Outlet branch pipe; 16. Second control valve; 17. Main circulating water outlet valve; 18. Main outlet valve; 19. Drain pump. Detailed Implementation

[0018] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0019] Please see Figure 1 and Figure 2 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components relevant to the present invention and are not drawn according to the actual number, shape, and size of components in implementation. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the component layout may be more complex. The structures, proportions, and sizes shown in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives of the present invention, should still fall within the scope of the technical content disclosed in the present invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are only for clarity of description and are not intended to limit the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0020] Please see Figure 1 and Figure 2This invention provides a cooling and sealing structure for the mechanical seal of a low-pressure condensate pump 19, comprising a condensate pump 19 and a condenser 5. The mechanical seal of the condensate pump has a high-pressure side and a low-pressure side. The inlets of the high-pressure and low-pressure sides of the condensate pump 19 are respectively connected to the makeup water pipes of the condenser 5. The makeup water pipes of the condenser 5 contain demineralized water. The outlets of the high-pressure and low-pressure sides of the condensate pump 19 are respectively connected to the condenser 5. By connecting the inlets of the high-pressure and low-pressure sides of the condensate pump 19 to the makeup water pipes of the condenser 5, which contain demineralized water, the use of demineralized water to cool the mechanical seal of the condensate pump 19 can prevent the water used to cool the mechanical seal from entering the condensate pump 19 and contaminating the condensate, thus reducing the risk of scaling on the boiler tube walls and turbine blades. Furthermore, the demineralized water used to cool the mechanical seal enters the condenser 5 at a suitable temperature and pressure. The recycling of the demineralized water used to cool the mechanical seal results in low energy consumption and strong applicability.

[0021] The condenser 5's makeup water pipe is connected to the drain pump 19 via a main water supply pipe 11 and branch water supply pipes 14. The main water supply pipe 11 is connected to the makeup water pipe of the condenser 5, and the branch water supply pipes 14 branch off from the main water supply pipe 11. The branch water supply pipes 14 are connected to the high-pressure and low-pressure inlets of the drain pump, respectively. A demineralized water supply main valve 12 is installed on the main water supply pipe 11. By installing the demineralized water supply main valve 12, the demineralized water can be easily opened and closed to control whether demineralized water enters the drain pump 19. It also allows for easy closure of the demineralized water supply main valve 12 during maintenance of the drain pump 19, preventing waste of demineralized water. The main water supply pipe 11 and branch water supply pipes 14 reduce the design and installation difficulty of the pipeline and decrease pipeline installation costs.

[0022] Specifically, the inlets of the high-pressure and low-pressure sides of the drain pump 19 are connected to the circulating water circuit via water supply branch pipes 14. The circulating water circuit has a circulating water main pipe 10, which is connected to the water supply branch pipes 14. A circulating water supply main valve 9 is installed on the circulating water main pipe 10. The outlets of the high-pressure and low-pressure sides of the drain pump 19 are connected to the circulating water outlet, which is equipped with a circulating water outlet main valve 17. The circulating water is discharged from the cooling and sealing structure of the mechanical seal of the drain pump 19 through the circulating water outlet. By connecting the water supply branch pipes 14 to the circulating water circuit, the circulating water can serve as a backup cooling water source, preventing the mechanical seal from burning out due to prolonged operation without cooling when the demineralized water supply is interrupted. When circulating water is needed to cool the mechanical seal of the condensate pump 19, close the demineralized water supply main valve 12 and the outlet main valve 18, and open the circulating water outlet main valve 17 and the circulating water supply main valve 9. Circulating water is then introduced into the high-pressure and low-pressure sides of the mechanical seal of the condensate pump 19 through the supply branch pipe 14, and then flows out from the circulating water outlet main valve 17 through the outlet branch pipe 15. By introducing circulating water into the mechanical seal of the condensate pump 19 and then allowing it to flow out from the circulating water outlet, it is possible to prevent circulating water from flowing into the condenser 5 and affecting the water quality of the condensate in the condenser 5. This also prevents circulating water from entering the boiler and turbine after entering the condenser 5, thus increasing the risk of scaling on the boiler tube walls and turbine blades.

[0023] Specifically, the condensate pump 19 is equipped with a first control valve 13 at the inlet of both the high-pressure and low-pressure sides, and a second control valve 16 at the outlet of both sides. The first control valve 13 allows for convenient adjustment of the water flow rate on both sides of the condensate pump 19, ensuring both cooling and sealing effects while maintaining efficient energy use. The second control valve 16 allows for simultaneous closure of both valves when the condensate pump 19 requires maintenance, facilitating maintenance operations.

[0024] The drain pump 19 has a main outlet pipe 8 and branch outlet pipes 15 connected to the condenser 5 at its high-pressure and low-pressure outlets, respectively. The branch outlet pipes 15 are connected to the high-pressure and low-pressure sides of the drain pump 19, and converge to form the main outlet pipe 8, which is connected to the condenser 5. A main outlet valve 18 is installed on the main outlet pipe 8, located near the drain pump 19. The branch outlet pipes 15 also converge to connect to the circulating water outlet. Because the circulating water contains dissolved calcium, magnesium, and bicarbonates, these substances decompose under high environmental temperatures, releasing white precipitates. These precipitates adhere to the boiler tube walls and turbine blades, affecting their normal operation. Therefore, when using circulating water to cool the mechanical seal of the drain pump 19, the circulating water must be drained. The main outlet pipe 8 and branch outlet pipes 15 reduce the difficulty of pipeline design and installation, and lower pipeline installation costs.

[0025] Specifically, a shut-off valve 7 is installed on the main outlet pipe 8, located near the condenser 5. When maintenance is required on the drain pump 19, the shut-off valve 7 can be closed to prevent gas from entering the condenser 5, which could cause a pressure increase and lead to a safety accident. Furthermore, the simultaneous closure of the shut-off valve 7 and the main outlet valve 18 provides double protection, ensuring that no gas enters the condenser 5 during maintenance of the drain pump 19.

[0026] In detail, both the main water supply pipe 11 and the branch water supply pipe 14 are made of stainless steel. Using stainless steel pipelines can prevent rust from entering the mechanical seal and causing wear and leakage on its sealing surface after the pipeline rusts, thereby improving the service life of the mechanical seal, thus enhancing the operational stability of the low-pressure heater condensate pump 19 and ensuring the stable operation of the turbine unit.

[0027] In detail, both the main outlet pipe 8 and the branch outlet pipe 15 are made of stainless steel. Using stainless steel pipes can prevent rust from entering the boiler and turbine after corrosion, thus preventing them from affecting normal operation.

[0028] The present invention also provides a cooling and sealing system for the mechanical seal of the low-pressure condensate pump 19, including the cooling and sealing structure of the mechanical seal of the low-pressure condensate pump 19 as described above.

[0029] In this embodiment, the low-pressure heater condensate pump 19 is installed in a mechanical seal cooling and sealing system consisting of a No. 5 low-pressure heater 1, a No. 6 low-pressure heater 2, and a No. 7 low-pressure heater 3, which are connected in sequence. The No. 7 low-pressure heater 3 is connected to the condenser 5 via a shaft seal heater 4 and a condensate pump 6. The condensate from the No. 5, No. 6, and No. 7 low-pressure heaters 1 and 2 flows back to the condenser 5 by gravity flow. A low-pressure heater condensate pump 19 is installed between the No. 5 and No. 6 low-pressure heaters 2. This pump directly pumps some of the condensate from the No. 6 low-pressure heater 2 into the No. 5 low-pressure heater 1, reducing heat loss from condensate flowing into the condenser 5 and improving the unit's thermal economy.

[0030] In summary, by connecting the high-pressure and low-pressure inlets of the condensate pump 19 to the makeup water pipes of the condenser 5, and using demineralized water in the makeup water pipes of the condenser 5 to cool the mechanical seal of the condensate pump 19, it is possible to prevent the water used to cool the mechanical seal of the condensate pump 19 from entering the condensate pump 19 and contaminating the condensate, thereby reducing the risk of scaling on the boiler tube walls and turbine blades. Furthermore, the demineralized water used to cool the mechanical seal enters the condenser 5 at a suitable temperature and pressure, and can be recycled, resulting in low energy consumption and strong applicability.

[0031] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A cooling and sealing structure for a low-pressure hydrophobic pump mechanical seal, characterized in that, The device includes a condensate pump and a condenser. The mechanical seal of the condensate pump has a high-pressure side and a low-pressure side. The inlets of the high-pressure side and the low-pressure side of the condensate pump are respectively connected to the water supply pipe of the condenser. The water supply pipe of the condenser contains demineralized water. The outlets of the high-pressure side and the low-pressure side of the condensate pump are respectively connected to the condenser. A main water supply pipe and a branch water supply pipe are provided between the water supply pipe of the condenser and the condensate pump. The main water supply pipe is connected to the water supply pipe of the condenser. The branch water supply pipe is connected to the high-pressure side and the low-pressure side inlet of the condensate pump respectively. A demineralized water supply main valve is provided on the main water supply pipe. The inlets of the high-pressure and low-pressure sides of the condensate pump are connected to the circulating water circuit through the water supply branch pipes. The circulating water circuit has a circulating water main pipe, which is connected to the water supply branch pipes. A circulating water supply main valve is installed on the circulating water main pipe. The outlets of the high-pressure and low-pressure sides of the condensate pump are connected to the circulating water outlet, which is equipped with a circulating water outlet main valve. The circulating water is discharged from the low-pressure condensate pump mechanical seal cooling sealing structure through the circulating water outlet. The high-pressure side and the low-pressure side of the condensate pump are respectively equipped with a first control valve at the inlet and the outlet of the high-pressure side and the low-pressure side of the condensate pump, respectively. A main outlet pipe and branch outlet pipes are provided between the outlets of the high-pressure side and the low-pressure side of the condenser and the condenser. The branch outlet pipes are respectively connected to the high-pressure side and the low-pressure side of the condenser. The branch outlet pipes converge to form the main outlet pipe, which is connected to the condenser. A main outlet valve is provided on the main outlet pipe, which is close to the condenser. After the branch outlet pipes converge, they are also connected to the circulating water outlet. A shut-off valve is also installed on the main outlet pipe, and the shut-off valve is located near the condenser.

2. The low-pressure hydrophobic pump mechanical seal cooling sealing structure according to claim 1, characterized in that: Both the main water supply pipe and the branch water supply pipes are made of stainless steel.

3. The low-pressure hydrophobic pump mechanical seal cooling sealing structure according to claim 1, characterized in that: Both the main water outlet pipe and the branch water outlet pipes are made of stainless steel.

4. A low-pressure condensate pump mechanical seal cooling and sealing system, characterized in that, Includes the low-pressure hydrophobic pump mechanical seal cooling sealing structure as described in any one of claims 1-3.

Images