Anti-flash evaporation heat recovery system and steam extraction system

Abstract

This disclosure relates to a flashover prevention heat recovery system and a steam extraction system. The flashover prevention heat recovery system includes a steam cooling condenser, a condensate cooler, an extraction pipe, a connecting pipe, and a cooling water inlet pipe. The steam cooling condenser has a steam inlet, a steam outlet, a first condensate inlet, and a first condensate outlet; the extraction pipe is connected to the steam inlet. The condensate cooler has a condensate inlet, a condensate outlet, a second condensate inlet, a second condensate outlet, and a cooling water inlet. The first end of the connecting pipe is connected to the steam outlet, the second end of the connecting pipe is connected to the condensate inlet, and the cooling water inlet pipe is connected to the cooling water inlet. This flashover prevention heat recovery system, through the cooling water inlet pipe, allows cooling water to be introduced separately to contact the condensate in the condensate cooler, quickly adjusting the temperature of the condensate and maintaining its subcooling, thereby promptly preventing the flashover accident from continuing.

Description

Technical Field

[0001] This disclosure relates to the field of thermal power generation technology, specifically to an anti-flash evaporation heat recovery system and a steam extraction system. Background Technology

[0002] In related technologies, the actual temperature of the condensate in the condensate cooler is often higher than the saturation temperature, which often leads to the problem of condensate flash evaporation. This can cause false liquid levels, which may trigger the liquid level protection to shut down the unit or even cause water to enter the turbine, resulting in serious damage to the unit. Summary of the Invention

[0003] The purpose of this disclosure is to provide a flashover-proof heat recovery system and a steam extraction system to solve the problems in the aforementioned related technologies.

[0004] To achieve the above objectives, one aspect of this disclosure provides a flashover-proof heat recovery system, including a steam cooling condenser, a condensate cooler, a steam extraction pipe, a connecting pipe, and a cooling water inlet pipe.

[0005] The steam cooling condenser has a steam inlet, a steam outlet, a first condensate inlet, and a first condensate outlet. The steam inlet is connected to the steam outlet, and the first condensate inlet is connected to the first condensate outlet. The steam extraction pipe is connected to the steam inlet and is used to extract steam.

[0006] The hydrophobic cooler has a hydrophobic inlet, a hydrophobic outlet, a second condensate inlet, a second condensate outlet, and a cooling water inlet. The hydrophobic inlet, the hydrophobic outlet, and the cooling water inlet are interconnected. The second condensate inlet and the second condensate outlet are interconnected. The first end of the connecting pipe is connected to the steam outlet, and the second end of the connecting pipe is connected to the hydrophobic inlet. The cooling water inlet pipe is connected to the cooling water inlet and can introduce cooling water to mix with the hydrophobic water in the hydrophobic cooler.

[0007] Optionally, the anti-flash evaporation heat recovery system further includes a shut-off valve connected to the cooling water inlet pipe, which can open or close the cooling water inlet pipe.

[0008] Optionally, the anti-flash evaporation heat recovery system further includes a throttling valve and a regulating valve, both of which are connected to the cooling water inlet pipe.

[0009] Optionally, the anti-flash evaporation heat recovery system further includes a pressure relief valve connected to the hydrophobic cooler and communicating with the hydrophobic inlet and the hydrophobic outlet.

[0010] Optionally, the anti-flash evaporation heat recovery system further includes a first check valve connected to the connecting pipe, which is used to restrict the backflow of condensate from the condensate cooler to the steam cooling condenser.

[0011] Optionally, the anti-flash evaporation heat recovery system further includes a pressure sensor, a temperature sensor, a liquid level sensor, and a controller. The pressure sensor, the temperature sensor, and the liquid level sensor are all connected to the hydrophobic cooler. The pressure sensor is used to detect the pressure of the condensate in the hydrophobic cooler, the temperature sensor is used to detect the temperature of the condensate in the hydrophobic cooler, and the liquid level sensor is used to detect the liquid level of the condensate in the hydrophobic cooler. The pressure sensor, the temperature sensor, the liquid level sensor, the shut-off valve, the regulating valve, the pressure relief valve, and the first check valve are all electrically connected to the controller.

[0012] Optionally, the anti-flash evaporation heat recovery system further includes a first condensate drain pipe and a second condensate drain pipe, both of which are connected to the condensate outlet. A first switching valve is provided on the first condensate drain pipe, and a second switching valve is provided on the second condensate drain pipe.

[0013] Optionally, the anti-flashover heat recovery system further includes a second check valve and a third switching valve, both of which are connected to the extraction pipe.

[0014] Optionally, the anti-flash evaporation heat recovery system further includes a condensate pump, a first condensate delivery pipe, a second condensate delivery pipe, and a third condensate delivery pipe. The first condensate delivery pipe is connected to the outlet of the condensate pump. The end of the first condensate delivery pipe away from the condensate pump is connected to the second condensate inlet. The first end of the second condensate delivery pipe is connected to the second condensate outlet. The second end of the second condensate delivery pipe is connected to the first condensate inlet. The third condensate delivery pipe is connected to the first condensate outlet. The end of the cooling water inlet pipe away from the hydrophobic cooler is connected to the first condensate delivery pipe.

[0015] A second aspect of this disclosure also provides a steam extraction system, including the aforementioned anti-flashover heat recovery system.

[0016] The above technical solution, through its cooling water inlet pipe, allows for independent contact between cooling water and the condensate from the condensate cooler. This enables rapid adjustment of the condensate temperature in the event of flash evaporation, maintaining its subcooling and ensuring its temperature remains below its saturation temperature under all operating conditions. This timely intervention prevents further flash evaporation, avoids triggering the liquid level protection system, ensures stable unit operation, and prevents major unit accidents. The combination of the condensate cooler and the steam cooling condenser provides dual heat exchange cooling, facilitating easy adjustment of the condensate in the condensate cooler without affecting the operation of the steam cooling condenser.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of an anti-flash evaporation heat recovery system according to one embodiment of the present disclosure.

[0020] Explanation of reference numerals in the attached figures

[0021] 1. Steam cooling condenser; 2. Drain cooler; 3. Steam extraction pipe; 4. Connecting pipe; 5. Cooling water inlet pipe; 6. Shut-off valve; 7. Throttling valve; 8. Regulating valve; 9. Pressure relief valve; 10. First check valve; 11. Pressure sensor; 12. Temperature sensor; 13. Liquid level sensor; 14. First drain pipe; 15. Second drain pipe; 16. First switch valve; 17. Second switch valve; 18. Second check valve; 19. Third switch valve; 20. Condensate pump; 21. First condensate delivery pipe; 22. Second condensate delivery pipe; 23. Third condensate delivery pipe. Detailed Implementation

[0022] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0023] In this disclosure, unless otherwise stated, directional terms such as "upper," "lower," "left," and "right" are generally used to define the orientation of the accompanying drawings, and "inner" and "outer" refer to the inner and outer parts of the relevant components. Furthermore, terms such as "first" and "second" are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] In the description of this disclosure, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can be a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0025] The steam turbine has nine non-regulating extraction steam sections, which are respectively delivered to the high-pressure heater, the low-pressure heater, and the steam-driven feedwater pump and auxiliary steam header. However, when the thermal power unit rapidly reduces load during peak shaving, the low-pressure heater extraction steam pressure drops rapidly. Due to the thermal inertia of the low-pressure heater, the rate of decrease in condensate temperature is lower than the rate of decrease in extraction steam pressure.

[0026] Therefore, the actual temperature of the condensate in the condensate cooler 2 in the related technology is often higher than the saturation temperature, which often leads to the problem of condensate flash evaporation. This can cause false liquid levels, which may trigger the liquid level protection to stop the unit from operating, or even cause water to enter the turbine and cause serious damage to the unit.

[0027] Therefore, such as Figure 1 As shown, one aspect of this disclosure provides a flashover-proof heat recovery system, including a steam cooling condenser 1, a condensate cooler 2, a steam extraction pipe 3, a connecting pipe 4, and a cooling water inlet pipe 5.

[0028] The steam cooling condenser 1 has a steam inlet, a steam outlet, a first condensate inlet, and a first condensate outlet. The steam inlet and the steam outlet are connected, and the first condensate inlet and the first condensate outlet are connected. The extraction pipe 3 is connected to the steam inlet and is used to extract steam.

[0029] The condensate cooler 2 has a condensate inlet, a condensate outlet, a second condensate inlet, a second condensate outlet, and a cooling water inlet. The condensate inlet, condensate outlet, and cooling water inlet are interconnected. The second condensate inlet and the second condensate outlet are also interconnected. The first end of the connecting pipe 4 is connected to the steam outlet, and the second end of the connecting pipe 4 is connected to the condensate inlet. The cooling water inlet pipe 5 is connected to the cooling water inlet and can introduce cooling water to mix with the condensate in the condensate cooler 2.

[0030] The extraction pipe 3, located away from the steam cooling condenser 1, is connected to the steam turbine for steam extraction, allowing steam to enter the steam cooling condenser 1, flow within it, and exit through the steam outlet. The first condensate inlet introduces condensate, which flows through the steam cooling condenser 1 and exits through the first condensate outlet. As the steam flows through the steam cooling condenser 1, it exchanges heat with the condensate, thus cooling the steam.

[0031] In this process, the steam cooled by the steam cooling condenser 1 forms condensate and enters the condensate cooler 2 from the steam outlet. The second condensate inlet allows condensate to flow in the condensate cooler 2 and exit from the second condensate outlet, thus enabling the condensate and condensate to exchange heat and cool each other again.

[0032] Among them, the cooling water inlet pipe 5 can independently introduce cooling water into the condensate cooler 2. When the condensate flashes and the liquid level rises suddenly, the cooling water introduced through the cooling water inlet pipe 5 can regulate the temperature of the condensate in the condensate cooler 2, maintain the subcooling of the condensate, and keep the temperature of the condensate below its saturation temperature under any operating conditions.

[0033] In the above technical solution, the cooling water inlet pipe 5 allows cooling water to be introduced separately and contact the condensate in the condensate cooler 2. This enables rapid adjustment of the condensate temperature in the event of flash evaporation in the condensate cooler 2, maintaining its subcooling and ensuring its temperature remains below its saturation temperature under all operating conditions. This timely intervention prevents further flash evaporation, avoids triggering the liquid level protection mechanism, ensures stable unit operation, and prevents major unit accidents. The condensate cooler 2 and the steam cooling condenser 1 achieve dual heat exchange cooling, allowing for convenient adjustment of the condensate in the condensate cooler 2 without affecting the operation of the steam cooling condenser 1.

[0034] Optionally, in one embodiment of this disclosure, the steam cooling condenser 1 includes a steam cooling section and a steam condensation section. The steam cooling condenser 1 includes a first tank body, and a first condensate flow pipe is provided inside the first tank body. The first condensate flow pipe is used to supply condensate flow and is connected to a first condensate inlet and a first condensate outlet respectively. The space inside the first tank body is used to contain steam. The steam inlet and the steam outlet are both connected to the internal space of the first tank body, so that the steam and the condensate flowing in the first condensate flow pipe can exchange heat.

[0035] Optionally, in one embodiment of this disclosure, the hydrophobic cooler 2 includes a second tank body, and a second condensate flow pipe is provided inside the second tank body. The second condensate flow pipe is used to supply condensate flow and is connected to a second condensate inlet and a second condensate outlet respectively. The space inside the second tank body is used to contain hydrophobic water. The hydrophobic water inlet, hydrophobic water outlet and cooling water inlet are all connected to the internal space of the second tank body, so that the hydrophobic water and the condensate flowing in the second condensate flow pipe can exchange heat.

[0036] Optionally, in one embodiment of this disclosure, the anti-flashover heat recovery system further includes a shut-off valve 6, which is connected to the cooling water inlet pipe 5. The shut-off valve 6 can open or close the cooling water inlet pipe 5. The shut-off valve 6 allows for convenient operation by opening when cooling water needs to be introduced into the condensate cooler 2 and closing when cooling water is not needed. In some examples, the shut-off valve 6 can be an electric ball valve or an electric butterfly valve.

[0037] Optionally, in one embodiment of this disclosure, the anti-flash evaporation heat recovery system further includes a throttle valve 7 and a regulating valve 8, both of which are connected to the cooling water inlet pipe 5.

[0038] The throttle valve 7 regulates the flow rate of the cooling water, and the regulating valve 8 regulates the pressure of the cooling water. This allows for convenient adjustment of the cooling water introduced into the condensate cooler 2 as needed, making it more convenient to use. In some examples, the regulating valve 8 may be a normally closed pneumatic regulating valve.

[0039] Optionally, in one embodiment of this disclosure, the anti-flash evaporation heat recovery system further includes a pressure relief valve 9, which is connected to the condensate cooler 2 and is connected to the condensate inlet and the condensate outlet.

[0040] The pressure relief valve 9 is capable of releasing pressure and venting gas. The pressure relief valve 9 is connected to the second tank in the above embodiment, so that the pressure rise caused by hydrophobic flash evaporation can be reduced by the pressure relief valve 9 to prevent the second tank from overpressure and ensure the safety of the hydrophobic cooler 2.

[0041] Optionally, in one embodiment of this disclosure, the anti-flash evaporation heat recovery system further includes a first check valve 10, which is connected to the connecting pipe 4. The first check valve 10 is used to restrict the backflow of condensate from the condensate cooler 2 to the steam cooling condenser 1. By setting the first check valve 10, when the condensate in the condensate cooler 2 flashes and the liquid level rises suddenly, the backflow of condensate from the condensate cooler 2 to the steam cooling condenser 1 can be restricted, thereby protecting the steam cooling condenser 1.

[0042] Optionally, in one embodiment of this disclosure, the anti-flash evaporation heat recovery system further includes a pressure sensor 11, a temperature sensor 12, a liquid level sensor 13, and a controller. The pressure sensor 11, temperature sensor 12, and liquid level sensor 13 are all connected to the hydrophobic cooler 2. The pressure sensor 11 is used to detect the pressure of the hydrophobic water in the hydrophobic cooler 2, the temperature sensor 12 is used to detect the temperature of the hydrophobic water in the hydrophobic cooler 2, and the liquid level sensor 13 is used to detect the liquid level of the hydrophobic water in the hydrophobic cooler 2. The pressure sensor 11, temperature sensor 12, liquid level sensor 13, shut-off valve 6, regulating valve 8, pressure relief valve 9, and first check valve 10 are all electrically connected to the controller.

[0043] The pressure data detected by pressure sensor 11, the temperature data detected by temperature sensor 12, and the liquid level data detected by liquid level sensor 13 can be transmitted to the controller. The controller can control the opening or closing of the shut-off valve 6, regulating valve 8, pressure relief valve 9, and first check valve 10 based on the detected pressure data, temperature data, and liquid level data.

[0044] Understandably, when the pressure sensor 11 detects that the pressure of the condensate in the hydrophobic cooler 2 exceeds the threshold, the controller can control the pressure relief valve 9 to release pressure and vent air. When the level sensor 13 detects a sudden rise in the condensate level in the hydrophobic cooler 2, the controller can control the first check valve 10 to open and the shut-off valve 6 to open, introducing cooling water into the hydrophobic cooler 2 through the cooling water inlet pipe 5 to slow down the flash evaporation of the condensate.

[0045] Optionally, in one embodiment of this disclosure, the anti-flash evaporation heat recovery system further includes a first condensate drain pipe 14 and a second condensate drain pipe 15, both of which are connected to a condensate outlet. A first switch valve 16 is provided on the first condensate drain pipe 14, and a second switch valve 17 is provided on the second condensate drain pipe 15.

[0046] The first condensate drain pipe 14 and the second condensate drain pipe 15 are both used to drain condensate. The first condensate drain pipe 14 is used to drain normal condensate, and the second condensate drain pipe 15 is used to drain emergency condensate. This arrangement allows for separate drainage of condensate, facilitating the recycling of condensate.

[0047] The first switching valve 16 can open or close the first drain pipe 14, and the second switching valve 17 can open or close the second drain pipe 15, so that the first drain pipe 14 or the second drain pipe 15 can be opened as needed.

[0048] In some examples, the first switching valve 16 and the second switching valve 17 can be solenoid valves. The first switching valve 16 and the second switching valve 17 can also be electrically connected to the controller described above, and the controller can control them.

[0049] Optionally, in one embodiment of this disclosure, the anti-flash evaporation heat recovery system further includes a second check valve 18 and a third switching valve 19, both of which are connected to the extraction pipe 3.

[0050] The second check valve 18 can prevent steam backflow in the steam cooling condenser 1, and the third switch valve 19 can adjust the opening or closing of the extraction pipe 3, so as to control whether steam extraction is performed.

[0051] In some examples, the second check valve 18 can be a pneumatic check valve, and the third on / off valve 19 can be an electric butterfly valve. A temperature sensor 12, a pressure sensor 11, and a level sensor 13 can also be installed in the steam cooling condenser 1.

[0052] Optionally, in one embodiment of this disclosure, the anti-flash evaporation heat recovery system further includes a condensate pump 20, a first condensate delivery pipe 21, a second condensate delivery pipe 22, and a third condensate delivery pipe 23. The first condensate delivery pipe 21 is connected to the outlet of the condensate pump 20. The end of the first condensate delivery pipe 21 away from the condensate pump 20 is connected to the second condensate inlet. The first end of the second condensate delivery pipe 22 is connected to the second condensate outlet. The second end of the second condensate delivery pipe 22 is connected to the first condensate inlet. The third condensate delivery pipe 23 is connected to the first condensate outlet. The end of the cooling water inlet pipe 5 away from the hydrophobic cooler 2 is connected to the first condensate delivery pipe 21.

[0053] The first condensate delivery pipe 21, the second condensate delivery pipe 22, and the third condensate delivery pipe 23 are all used to supply condensate flow, and the condensate pump 20 is used to drive the condensate flow.

[0054] By connecting the cooling water inlet pipe 5 to the first condensate delivery pipe 21, condensate enters the cooling water inlet pipe 5 and then enters the hydrophobic cooler 2.

[0055] A second aspect of this disclosure also provides a steam extraction system, including the aforementioned anti-flashover heat recovery system.

[0056] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0058] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A flashover-prevention heat recovery system, characterized in that, It includes a steam cooling condenser, a condensate cooler, a steam extraction pipe, a connecting pipe, and a cooling water inlet pipe; The steam cooling condenser has a steam inlet, a steam outlet, a first condensate inlet, and a first condensate outlet. The steam inlet is connected to the steam outlet, and the first condensate inlet is connected to the first condensate outlet. The steam extraction pipe is connected to the steam inlet and is used to extract steam. The hydrophobic cooler has a hydrophobic inlet, a hydrophobic outlet, a second condensate inlet, a second condensate outlet, and a cooling water inlet. The hydrophobic inlet, the hydrophobic outlet, and the cooling water inlet are interconnected. The second condensate inlet and the second condensate outlet are interconnected. The first end of the connecting pipe is connected to the steam outlet, and the second end of the connecting pipe is connected to the hydrophobic inlet. The cooling water inlet pipe is connected to the cooling water inlet and can introduce cooling water to mix with the hydrophobic water in the hydrophobic cooler. The system includes a pressure sensor, a temperature sensor, a liquid level sensor, and a controller. The pressure sensor, temperature sensor, and liquid level sensor are all connected to the hydrophobic cooler. The pressure sensor is used to detect the pressure of the hydrophobic water inside the hydrophobic cooler. The temperature sensor is used to detect the temperature of the hydrophobic water inside the hydrophobic cooler. The liquid level sensor is used to detect the liquid level of the hydrophobic water inside the hydrophobic cooler. The pressure sensor, temperature sensor, and liquid level sensor are all electrically connected to the controller.

2. The anti-flash evaporation heat recovery system according to claim 1, characterized in that, The anti-flash evaporation heat recovery system also includes a shut-off valve, which is connected to the cooling water inlet pipe and can open or close the cooling water inlet pipe.

3. The anti-flash evaporation heat recovery system according to claim 2, characterized in that, The anti-flash evaporation heat recovery system also includes a throttling valve and a regulating valve, both of which are connected to the cooling water inlet pipe.

4. The anti-flashover heat recovery system according to claim 3, characterized in that, The anti-flash evaporation heat recovery system also includes a pressure relief valve, which is connected to the hydrophobic cooler and communicates with the hydrophobic inlet and the hydrophobic outlet.

5. The anti-flash evaporation heat recovery system according to claim 4, characterized in that, The anti-flash evaporation heat recovery system also includes a first check valve, which is connected to the connecting pipe and is used to restrict the backflow of condensate from the condensate cooler to the steam cooling condenser.

6. The flashover prevention heat recovery system according to claim 5, characterized in that, The shut-off valve, the regulating valve, the pressure relief valve, and the first check valve are all electrically connected to the controller.

7. The flashover prevention heat recovery system according to claim 1, characterized in that, The anti-flash evaporation heat recovery system also includes a first condensate drain pipe and a second condensate drain pipe, both of which are connected to the condensate outlet. A first switch valve is provided on the first condensate drain pipe, and a second switch valve is provided on the second condensate drain pipe.

8. The anti-flash evaporation heat recovery system according to claim 1, characterized in that, The anti-flash evaporation heat recovery system also includes a second check valve and a third switching valve, both of which are connected to the extraction pipe.

9. The anti-flash evaporation heat recovery system according to any one of claims 1-8, characterized in that, The anti-flash evaporation heat recovery system further includes a condensate pump, a first condensate delivery pipe, a second condensate delivery pipe, and a third condensate delivery pipe. The first condensate delivery pipe is connected to the outlet of the condensate pump. The end of the first condensate delivery pipe away from the condensate pump is connected to the second condensate inlet. The first end of the second condensate delivery pipe is connected to the second condensate outlet. The second end of the second condensate delivery pipe is connected to the first condensate inlet. The third condensate delivery pipe is connected to the first condensate outlet. The end of the cooling water inlet pipe away from the hydrophobic cooler is connected to the first condensate delivery pipe.

10. A steam extraction system, characterized in that, Includes the anti-flash evaporation heat recovery system as described in any one of claims 1-9.

Images