Cooling system and method for flue gas condensate water

Abstract

The embodiment of the invention provides a cooling system and method for flue gas condensate water. The cooling system comprises a flue gas condensate water collecting pool; the flue gas condensate water reservoir is used for storing the cooled flue gas condensate water; the booster pump is used for pumping flue gas condensate water in the flue gas condensate water collecting pool to an inlet of the air cooling heat exchanger through a water supply pipeline; the air cooling heat exchanger is used for preliminarily cooling flue gas condensate water, and an outlet of the air cooling heat exchanger communicates with an inlet of the wet cooling tower through a water outlet pipeline; the wet cooling tower is used for carrying out secondary cooling on outlet water from the air cooling heat exchanger, and an outlet of the wet cooling tower is communicated with the flue gas condensate water reservoir through a water conveying pipeline; the bypass pipeline communicates with the water outlet pipeline and the water conveying pipeline. The bypass control valve is arranged on the bypass pipeline and is electrically connected with the control device; the control device is used for controlling the opening and closing states of the bypass control valve according to preset conditions so as to control whether outlet water of the air cooling heat exchanger flows through the wet cooling tower or not for secondary cooling.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the technical field of cooling equipment, and specifically relate to a cooling system and method for flue gas condensate water. Background Art

[0002] The water intake device after the furnace recovers the water discharged from the flue gas through heat exchange cooling. The water quality of the flue gas condensate after the furnace is monitored. Except for the pH value, the other water quality indicators are better than the city water, which can be used as the water source for chemical water production.

[0003] Because the temperature of flue gas condensate is in the range of 37.5-50℃, the membrane components, resins, etc. of the chemical water production system require the inlet water temperature to be in the range of 22-28℃. Flue gas condensate cannot be used directly as a water source for water production, but can only be used after mixing with reclaimed water and cooling it down.

[0004] In order to improve the utilization rate of flue gas condensate and reduce production costs, how to reduce the temperature of flue gas condensation has become a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0005] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a cooling system and method for flue gas condensate water.

[0006] According to a first aspect of an embodiment of the present disclosure, a cooling system for flue gas condensate water is provided, comprising:

[0007] A flue gas condensate collection pool, wherein the flue gas condensate collection pool is used to collect flue gas condensate;

[0008] A flue gas condensate water reservoir, wherein the flue gas condensate water reservoir is used to store the flue gas condensate after cooling;

[0009] A booster pump, the booster pump is used to pump the flue gas condensate in the flue gas condensate collection pool to the inlet of the air-cooled heat exchanger through a water supply pipeline;

[0010] An air-cooled heat exchanger, the air-cooled heat exchanger is used to preliminarily cool the flue gas condensate, and the outlet of the air-cooled heat exchanger is connected to the inlet of the wet cooling tower through a water outlet pipeline;

[0011] A wet cooling tower, the wet cooling tower is used to perform secondary cooling on the outlet water from the air-cooled heat exchanger, and the outlet of the wet cooling tower is connected to the flue gas condensate water reservoir through a water pipeline;

[0012] A bypass pipeline, the bypass pipeline connecting the water outlet pipeline and the water delivery pipeline;

[0013] a bypass control valve, the bypass control valve being arranged on the bypass pipeline and being electrically connected to the control device; and,

[0014] A control device is used to control the opening and closing states of the bypass control valve according to preset conditions to control whether the outlet water of the air-cooled heat exchanger flows through the wet cooling tower for secondary cooling.

[0015] Optionally, the preset condition includes a temperature condition; the cooling system further includes a first temperature detection element, which is arranged at the outlet of the air-cooled heat exchanger and is electrically connected to the control device, and is used to detect the temperature of the flue gas condensate after being cooled by the air-cooled heat exchanger;

[0016] Wherein, the control device controls the opening and closing state of the bypass control valve according to the comparison between the actual condensed water temperature value detected by the first temperature detection element and the first preset condensed water temperature value.

[0017] Optionally, the preset condition includes a temperature condition; the cooling system further includes a second temperature detection element, the second temperature detection element is electrically connected to the control device and is used to detect the ambient temperature;

[0018] Wherein, the control device controls the opening and closing state of the bypass control valve according to the comparison between the actual ambient temperature value detected by the second temperature detection element and the preset ambient temperature value.

[0019] Furthermore, it also includes:

[0020] A recirculation pipeline, the recirculation pipeline is connected to the water outlet pipeline and the flue gas condensate collection tank;

[0021] A recirculation control valve, the recirculation control valve is electrically connected to the control device; wherein the control device is used to control the opening and closing states of the recirculation control valve according to preset conditions, so as to control whether the outlet water of the air-cooled heat exchanger flows through the air-cooled heat exchanger again for circulating cooling.

[0022] Optionally, the preset conditions include temperature conditions; when the first temperature detection element is provided at the outlet of the air-cooled heat exchanger, the control device controls the opening and closing state of the recirculation control valve based on a comparison between an actual condensed water temperature value detected by the first temperature detection element and a second preset condensed water temperature value.

[0023] Optionally, there are two air-cooled heat exchangers, which are connected in parallel, and the inlets of the two air-cooled heat exchangers are respectively connected to the water supply pipeline, and the outlets of the two air-cooled heat exchangers are respectively connected to the water outlet pipeline.

[0024] Furthermore, it also includes:

[0025] A regulating valve is arranged in a pipeline at the inlet of the wet cooling tower and is electrically connected to the control device; wherein the control device controls the regulating valve to adjust the flow rate flowing into the wet cooling tower.

[0026] A second aspect of an embodiment of the present disclosure provides a method for cooling flue gas condensate water, the method being implemented according to the above-mentioned cooling system for flue gas condensate water, comprising:

[0027] Detecting the temperature of flue gas condensate after being cooled by the air-cooled heat exchanger;

[0028] Comparing the detected actual condensed water temperature value with the first preset condensed water temperature value;

[0029] The opening and closing states of the bypass control valve are controlled according to the comparison results.

[0030] Optionally, controlling the opening and closing state of the bypass control valve according to the comparison result includes:

[0031] According to the comparison result that the actual condensed water temperature value is lower than the first preset condensed water temperature value, the bypass control valve on the bypass pipeline is controlled to open, so that the flue gas condensed water flow bypasses the wet cooling tower through the bypass pipeline and flows into the flue gas condensed water storage tank;

[0032] According to the comparison result that the actual condensate water temperature value is higher than or equal to the first preset condensate water temperature value, the bypass control valve on the bypass pipeline is controlled to close, so that the flue gas condensate water flow passes through the wet cooling tower for secondary cooling, and the cooled flue gas condensate flows into the flue gas condensate water reservoir.

[0033] Furthermore, it also includes:

[0034] Detect ambient temperature;

[0035] Comparing the detected actual ambient temperature value with a preset ambient temperature value;

[0036] The opening and closing states of the bypass control valve are controlled according to the comparison results.

[0037] The beneficial effects of the embodiments of the present disclosure include:

[0038] In the present invention, the flue gas condensate water can be initially cooled by the air-cooled heat exchanger, and the water temperature of the flue gas condensate water can be effectively reduced. In addition, the wet cooling tower is connected in series with the air-cooled heat exchanger, and the flue gas condensate water flowing through the outlet of the air-cooled heat exchanger can be further cooled, wherein the control device controls whether the flue gas condensate water flowing out of the outlet of the air-cooled heat exchanger needs secondary cooling according to preset conditions. Through the above-mentioned setting method, the effective cooling of the flue gas condensate water can be guaranteed, so as to achieve the purpose of recycling and utilization, which can fully alleviate the contradiction between power generation and water ecological protection, and provide a feasible solution for thermal power plants in water-scarce areas to achieve maximum water conservation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a structural schematic diagram of a cooling system for flue gas condensate water according to an embodiment of the present disclosure;

[0040] Figure 2 The present invention is a schematic flow chart of a method for cooling flue gas condensate water according to an embodiment of the present invention.

[0041] In the figure, 1. Flue gas condensate collection tank; 2. Booster pump; 3. Water supply pipeline; 4. Air-cooled heat exchanger; 5. Water outlet pipeline; 6. Wet cooling tower; 7. Water supply pipeline; 8. Flue gas condensate storage tank; 9. Bypass pipeline; 10. Bypass control valve; 11. First temperature detection element; 12. Recirculation pipeline; 13. Recirculation control valve; 14. Regulating valve. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0043] The following is a further detailed description of the implementation methods of the present application in conjunction with the accompanying drawings and examples. The detailed descriptions and drawings of the following examples are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments. In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "multiple" is more than two; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inside", "outside", etc. is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the error tolerance range. "Parallel" is not parallel in the strict sense, but within the error tolerance range.

[0044] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0045] like Figure 1 As shown, a cooling system for flue gas condensate water includes a flue gas condensate water collection pool 1, a flue gas condensate water storage pool 8, a booster pump 2, an air-cooled heat exchanger 4, a wet cooling tower 6, a bypass pipeline 9, a bypass control valve 10 and a control device (not shown in the figure).

[0046] The flue gas condensate collection pool 1 is used to collect flue gas condensate, the flue gas condensate storage tank 8 is used to store the flue gas condensate after cooling, and the booster pump 2 is used to pump the flue gas condensate in the flue gas condensate collection pool 1 to the inlet of the air-cooled heat exchanger 4 through the water supply pipeline 3.

[0047] The air-cooled heat exchanger 4 is used for preliminary cooling of the flue gas condensate water. The outlet of the air-cooled heat exchanger 4 is connected to the inlet of the wet cooling tower 6 through the outlet water pipeline 5. The wet cooling tower 6 is used for secondary cooling of the outlet water from the air-cooled heat exchanger 4. The outlet of the wet cooling tower 6 is connected to the flue gas condensate water storage tank 8 through the water supply pipeline 7. The bypass pipeline 9 connects the outlet water pipeline 5 and the water supply pipeline 7.

[0048] The bypass control valve 10 is arranged on the bypass pipeline 9 and is electrically connected to the control device, which is used to control the opening and closing state of the bypass control valve 10 according to preset conditions to control whether the outlet water of the air-cooled heat exchanger 4 flows through the wet cooling tower 6 for secondary cooling.

[0049] In the present invention, the flue gas condensate water can be initially cooled by the air-cooled heat exchanger 4, and the water temperature of the flue gas condensate water can be effectively reduced. In addition, the wet cooling tower 6 is connected in series with the air-cooled heat exchanger 4, and the flue gas condensate water flowing through the outlet of the air-cooled heat exchanger 4 can be further cooled, wherein the control device controls whether the flue gas condensate water flowing out of the outlet of the air-cooled heat exchanger 4 needs secondary cooling according to preset conditions. Through the above-mentioned setting method, the effective cooling of the flue gas condensate water can be guaranteed, so as to achieve the purpose of recycling and utilization, which can fully alleviate the contradiction between power generation and water ecological protection, and provide a feasible solution for thermal power plants in water-scarce areas to achieve maximum water conservation.

[0050] The cooling system of the present invention can be applied to coal-fired units in northern areas with scarce water resources and coal-fired units in coastal areas with scarce fresh water resources.

[0051] In some embodiments, the preset conditions include temperature conditions, and the cooling system also includes a first temperature detection element 11, which is arranged at the outlet of the air-cooled heat exchanger 4 and is electrically connected to the control device, and is used to detect the temperature of the flue gas condensate water after being cooled by the air-cooled heat exchanger 4.

[0052] The control device controls the opening and closing state of the bypass control valve 10 according to the comparison between the actual condensed water temperature value detected by the first temperature detection element 11 and the first preset condensed water temperature value.

[0053] In the present invention, by setting the first temperature detection element 11 at the outlet of the air-cooled heat exchanger 4, the system can monitor the temperature of the flue gas condensate water after the initial cooling in real time. According to the comparison result of the actual condensate water temperature and the preset temperature value, the control device can respond quickly and dynamically adjust the state of the bypass control valve 10 to determine whether the flue gas condensate water needs to be cooled again.

[0054] When the actual condensed water temperature value is lower than the preset temperature threshold, the control system controls the bypass control valve 10 to open through the control device, so that the flue gas condensed water flows through the bypass pipeline 9 to bypass the wet cooling tower 6 and directly enter the flue gas condensed water reservoir 8, thereby avoiding unnecessary secondary cooling and saving energy. If the actual condensed water temperature value is higher than or equal to the preset temperature threshold, the control system controls the bypass control valve 10 to close through the control device, so that the water flows through the wet cooling tower 6 for secondary cooling to ensure that the required cooling effect is achieved. Specifically, when the bypass control valve 10 is opened, the resistance in the bypass pipeline 9 is designed to be less than the resistance of the wet cooling tower 6 pipeline, so that the flue gas condensed water flows into the flue gas condensed water reservoir 8 through the bypass pipeline.

[0055] In some embodiments, the preset condition includes a temperature condition, and the cooling system further includes a second temperature detection element, which is electrically connected to the control device and is used to detect the ambient temperature.

[0056] The control device controls the opening and closing state of the bypass control valve 10 according to the comparison between the actual ambient temperature value detected by the second temperature detection element and the preset ambient temperature value.

[0057] In the present invention, by monitoring the ambient temperature, the system can automatically adjust the working mode according to the changes in external conditions, thereby enhancing the adaptability of the system. In different seasons or weather conditions, the system can optimize the cooling strategy according to the actual ambient temperature to ensure efficient operation in any environment.

[0058] When the detected ambient temperature is low (lower than the preset ambient temperature value), the control system controls the bypass control valve 10 to open through the control device, so that the flue gas condensate water flow bypasses the wet cooling tower 6 through the bypass pipeline and directly enters the flue gas condensate water reservoir 8, thereby avoiding unnecessary secondary cooling and saving energy. If the actual ambient temperature is higher than or equal to the preset ambient temperature value, the control system controls the bypass control valve 10 to close through the control device, so that the flue gas condensate water flow passes through the wet cooling tower 6 for secondary cooling to ensure that the required cooling effect is achieved.

[0059] In some embodiments, the cooling system further includes a recirculation line 12 and a recirculation control valve 13 .

[0060] The recirculation pipeline 12 is connected to the water outlet pipeline 5 and the flue gas condensate collection pool 1, and the recirculation control valve 13 is electrically connected to the control device, wherein the control device is used to control the opening and closing states of the recirculation control valve 13 according to preset conditions to control whether the outlet water of the air-cooled heat exchanger 4 flows through the air-cooled heat exchanger 4 again for circulation cooling.

[0061] When the air-cooled heat exchanger 4 fails to cool the flue gas condensate to a sufficiently low temperature, the system controls the opening state of the recirculation control valve 13 through the control device, so that the flue gas condensate can be reintroduced into the air-cooled heat exchanger 4 through the recirculation pipeline 12 for secondary cooling, ensuring that the final outlet water temperature meets the standard. According to the actual detected conditions (such as the outlet temperature of the air-cooled heat exchanger 4), the control system can flexibly open or close the recirculation control valve 13 to ensure that the optimal cooling effect can be achieved under different working conditions.

[0062] By intelligently controlling the recirculation process (through control devices), the system can minimize energy consumption and avoid unnecessary repeated cooling while ensuring cooling effects. The recirculation mechanism can make full use of the cooling capacity of existing equipment, reduce dependence on additional cooling equipment, and improve overall energy efficiency.

[0063] In some embodiments, the preset conditions include temperature conditions. When a first temperature detection element 11 is provided at the outlet of the air-cooled heat exchanger 4, the control device controls the opening and closing state of the recirculation control valve 13 based on a comparison between an actual condensed water temperature value detected by the first temperature detection element 11 and a second preset condensed water temperature value.

[0064] In the present invention, by setting a first temperature detection element 11 at the outlet of the air-cooled heat exchanger 4, the system can monitor the temperature of the flue gas condensate water after preliminary cooling in real time, and accurately control the opening and closing state of the recirculation control valve 13 according to the comparison result between the actual temperature and the second preset temperature value.

[0065] When the detected actual condensed water temperature value is lower than the preset condensed water temperature, the control device controls the recirculation control valve 13 on the recirculation pipeline 12 to close, so that the flue gas condensed water flow continues to flow into the downstream pipeline, thereby avoiding unnecessary secondary cooling and saving energy. If the actual condensed water temperature value is higher than or equal to the preset condensed water temperature value, the control device controls the recirculation control valve 13 on the recirculation pipeline 12 to open, so that the flue gas condensed water flow circulates back to the air-cooled heat exchanger 4 through the recirculation pipeline 12 for circulation cooling, ensuring that the required cooling effect is achieved. Specifically, when the recirculation control valve 13 is opened, the resistance in the recirculation pipeline 12 is designed to be less than the resistance of the outlet pipeline 5, so that the flue gas condensed water flows into the flue gas condensed water collection tank 1 through the recirculation pipeline 12, and circulates back to the air-cooled heat exchanger 4 for circulation cooling again through the booster pump 2.

[0066] In some embodiments, there are two air-cooling heat exchangers 4 , which are connected in parallel, and the inlets of the two air-cooling heat exchangers 4 are respectively connected to the water supply pipeline 3 , and the outlets of the two air-cooling heat exchangers 4 are respectively connected to the water outlet pipeline 5 .

[0067] In the present invention, the two air-cooled heat exchangers 4 connected in parallel can handle a larger flow rate at the same time, thereby improving the overall cooling capacity of the system, and are suitable for scenarios with high load or large-scale cooling requirements. According to the actual working conditions, the control system can flexibly distribute the load between the two heat exchangers as needed, optimize the cooling effect, and avoid overloading a single heat exchanger. The two air-cooled heat exchangers 4 connected in parallel provide redundancy, and even if one of the heat exchangers fails or requires maintenance, the other can continue to work to ensure the continuous operation of the system.

[0068] In some embodiments, the cooling system further includes a regulating valve 14 , which is disposed in a pipeline at the inlet of the wet cooling tower 6 and is electrically connected to a control device, wherein the control device controls the regulating valve 14 to adjust the flow rate flowing into the wet cooling tower 6 .

[0069] In the present invention, the control device accurately controls the flow rate of the regulating valve 14 entering the wet cooling tower 6 according to actual needs, ensuring that the wet cooling tower 6 always operates in the best working state. The regulating valve 14 can prevent the wet cooling tower 6 from being overloaded due to excessive flow or from having a poor cooling effect due to insufficient flow, thereby optimizing the cooling efficiency of the entire system.

[0070] Specifically, the control device controls the opening of the regulating valve 14 according to parameters such as temperature, pressure or flow rate to adjust the flow rate flowing into the wet cooling tower 6.

[0071] In some embodiments, the saturated air discharged from the wet cooling tower (wet cooling tower 6) during operation forms visible white mist, which has a certain impact on the environment around the cooling tower. In particular, the white mist generated by the cooling tower in northern regions in winter has a greater impact. In order to avoid the impact of the white mist generated by the wet cooling tower on the surrounding environment, a closed dry-wet mixed operation cooling tower is adopted that combines efficient cooling, elimination of white mist, and maximum water-saving operation technology.

[0072] In the dry / wet combined operation mode, sensible heat and latent heat of evaporation are utilized. Compared with traditional evaporation equipment, the tendency of white fog is greatly reduced even under peak conditions, and a large amount of water can be saved.

[0073] In some embodiments, flue gas condensate is used to replenish water for the desulfurization system, and other production water uses recycled water. After the flue gas condensate is used to prepare desalted water, the water use principle is changed to chemical water production using all flue gas condensate, desulfurization and other systems use flue gas condensate first, and the insufficient part is supplemented with urban water.

[0074] As the utilization rate of flue gas condensate water has increased significantly and the purchase of grey water has been significantly reduced, there is no need to replenish grey water under non-extreme climatic conditions such as spring and autumn, and the supply of flue gas condensate water can be achieved to meet usage needs.

[0075] A specific example provided by the present invention includes:

[0076] The cooling system adopts a closed dry-wet mixed cooling tower (wet cooling tower 6), and adopts a flue gas condensate collection pool 1 + air-cooled heat exchanger 4 + wet cooling tower 6 solution.

[0077] Two booster pumps 2, two air-cooled heat exchangers 4 (each air-cooled heat exchanger 4 has six air-cooled units) and one wet cooling tower 6 are set up in the open air. Each booster pump 2 is connected to the water supply pipeline 3 through a pipeline. The water supply pipeline 3 is provided with an electromagnetic flowmeter 15 for detecting the flow in the water supply pipeline 3. Considering the corrosion and antifreeze issues, all the flow-through parts are made of 316L stainless steel, including but not limited to pipelines and valves. Furthermore, the cooling system is also provided with a purging Roots blower. After the cooling system is shut down, the water accumulated in the flow-through parts can be drained in a short time through the blower.

[0078] Each booster pump 2 is provided with a reducing device 18 (shown in the figure) on its pipeline. Also known as a reducer, used for connecting pipes of different diameters), check valve 19 (shown in the figure ) and a manual valve (Manual Valve abbreviation M) 20. Furthermore, a reducing device 18 and a manual valve 20 are respectively provided on the pipelines at the inlet and outlet ends of each air-cooled heat exchanger 4, and the manual valve 20 is used for manual flow adjustment by the operator. Furthermore, a pumping equipment (PE Pump Equipment) 16 is also provided on the outlet pipeline 5 to promote the flow of fluid in the outlet pipeline 5 to ensure the normal flow of fluid in the cooling system.

[0079] The recirculation pipeline 12 is provided with a manual valve, which is located upstream of the recirculation control valve 13 and is used for an operator to manually control the flow in the recirculation pipeline 12 .

[0080] A manual valve is provided on the bypass pipeline 9, and the manual valve is located upstream of the bypass control valve 10, and is used for an operator to manually control the flow in the bypass pipeline 9. The bypass pipeline 9 is connected to the water delivery pipeline 7 through a reducing device.

[0081] The inlet pipeline and the outlet pipeline of the wet cooling tower 6 are respectively provided with manual valves, wherein the manual valve of the inlet pipeline of the wet cooling tower 6 is located upstream of the regulating valve 14 , and a reducing device is also provided between the manual valve and the regulating valve 14 .

[0082] There are two flue gas condensate water storage tanks 8, each of which is connected to the water supply pipeline 7 through a pipeline. Each water supply pipeline 7 is respectively provided with a driving device (Motor abbreviation M), specifically a motor, which is used to drive the solenoid valve on the pipeline to adjust the flow rate of flue gas condensate flowing into the flue gas condensate water storage tank 8.

[0083] The air-cooled heat exchanger 4 is the main cooling equipment. All high-temperature flue gas condensate water passes through the air-cooled heat exchanger 4 for preliminary cooling at all times. A cooling fan is configured under each air-cooled unit of the air-cooled heat exchanger 4. During operation, the flue gas condensate water flows in from the water inlet pipe at the upper part of the water inlet chamber of the air-cooled unit, and is cooled through multiple processes in the air-cooled heat exchanger 4. Finally, it flows out from the water outlet pipe at the lower part of the water outlet chamber of the air-cooled heat exchanger 4 and merges into the water outlet pipeline 5. The control device adjusts the number and frequency of operation of the cooling fan according to the operating water volume and the outlet water temperature.

[0084] The temperature of flue gas condensate is generally 37.5-50°C. The membrane components, resins, etc. of the chemical water production system require the inlet water temperature to be within the range of 22-28°C. The outlet temperature of the air-cooled heat exchanger 4 is detected by the first temperature detection element 11 (the temperature detection element is also called the temperature element, Temperature Element or Temperature Transmitter TE) and displayed by the temperature indicator (Temperature Indicator TI). When the ambient temperature is higher than 18°C ​​(the preset ambient temperature value) for a long time or the outlet water temperature of the air-cooled heat exchanger 4 is higher than 25°C (the first preset condensate temperature value) for a long time, the outlet water of the air-cooled heat exchanger 4 needs to be connected in series with the wet cooling tower 6. Specifically, the control device controls the bypass control valve 10 to close according to the comparison between the actual condensate temperature value detected by the temperature or the actual ambient temperature value and the preset temperature, so that the outlet water of the air-cooled heat exchanger 4 flows into the wet cooling tower 6 for secondary cooling. On the contrary, the bypass control valve 10 is controlled to open, so that the outlet water of the air-cooled heat exchanger 4 flows into the flue gas condensate water storage tank 8.

[0085] When the outlet water temperature of the air-cooled heat exchanger 4 is higher than 30°C (the second preset condensed water temperature value), the control device controls the recirculation control valve 13 to open according to the comparison between the actual condensed water temperature value detected by the temperature and the preset temperature, so that the outlet water of the air-cooled heat exchanger 4 is circulated back to the flue gas condensed water collection pool 1 for circulating cooling. On the contrary, the bypass control valve 10 is controlled to close, so that the outlet water of the air-cooled heat exchanger 4 flows downstream through the outlet water pipeline 5.

[0086] The outlet water of the air-cooled heat exchanger 4 is sprayed from the top of the wet cooling tower 6, and then evenly dispersed by the filler and sprayed onto the water collecting tray. At the same time, the fan of the wet cooling tower 6 blows air from bottom to top in the opposite direction of the water flow. The water film on the filler is in extensive contact with the cold air, and mass transfer and heat transfer process occur, thereby achieving the purpose of reducing the water temperature of the flue gas condensate.

[0087] After the high-temperature flue gas condensate is adjusted by adding alkali, it enters the flue gas condensate collection pool 1, and is sent to the air-cooled heat exchanger 4 for cooling through the booster pump 2. Whether to perform spray cooling is determined according to the outlet water temperature. The specific judgment logic refers to the above implementation process. If necessary, the outlet water enters the wet cooling tower 6 through the wet cooling tower 6 inlet pipe and is spray cooled (the fan is started). The cooled outlet water enters the two flue gas condensate storage tanks 8. If not necessary, it directly enters the flue gas condensate storage tank 8 through the bypass pipe.

[0088] In the present invention, the above-mentioned cooling system is utilized to optimize the cooling of the condensed water recovered from the flue gas for deep utilization, thereby improving the utilization rate of the flue gas condensed water and reducing production costs. It also effectively reduces the water consumption of the coal-fired unit, realizes the environmentally friendly and energy-saving operation of the coal-fired unit, and creates significant water-saving, environmental protection, economic and social benefits.

[0089] The present invention effectively reduces the temperature of flue gas condensate water, increases the utilization space of flue gas condensate water, and also reduces the amount of purchased reclaimed water, thereby reducing the cost of power generation. In addition, due to the water production capacity of the sewage treatment plant, equipment defects, and water use conditions of surrounding users, the water supply situation in the plant is tight, and the risk of hidden dangers of water shortage in production and operation is significantly reduced. At the same time, due to the poor quality of urban reclaimed water and the large fluctuations in water quality due to seasonal changes, the problems of short water production cycle, frequent defects, frequent operations such as chemical cleaning and regeneration, low equipment standby rate, and large maintenance workload in the operation of water production equipment are also effectively controlled.

[0090] The large-scale, extensive and high-quality recycling of flue gas condensate reduces the consumption of natural water resources, creates good conditions for protecting water resources, fully alleviates the contradiction between power generation and water ecological protection, and provides a good example for thermal power plants in water-scarce areas to achieve maximum water conservation. It also effectively reduces the water consumption of coal-fired units and realizes environmentally friendly and energy-saving operation of the units. In practicing ecological civilization, creating a new path for the coordinated development of clean energy and green ecology, it promotes energy conservation, emission reduction, quality improvement and efficiency increase to a new level. It has a wide range of promotion significance for thermal power units in water-scarce areas.

[0091] refer to Figure 2 According to a second aspect of an embodiment of the present disclosure, a method for cooling flue gas condensate water is provided. The method is implemented according to the above-mentioned cooling system for flue gas condensate water, and includes:

[0092] S101. Detect the temperature of flue gas condensate after being cooled by an air-cooled heat exchanger.

[0093] S102: Compare the detected actual condensed water temperature value with the first preset condensed water temperature value.

[0094] S103. Control the opening and closing state of the bypass control valve according to the comparison result.

[0095] In the present invention, by monitoring the temperature of the flue gas condensate after cooling and comparing the actual condensate temperature with the preset temperature value, the control device can respond quickly and dynamically adjust the state of the bypass control valve to ensure that the system is always in the best working state.

[0096] In some embodiments, step S103 controls the opening and closing states of the bypass control valve according to the comparison result, including: according to the comparison result that the actual condensate temperature value is lower than the first preset condensate temperature value, controlling the bypass control valve on the bypass pipe to open, so that the flue gas condensate water flow bypasses the wet cooling tower through the bypass pipe and flows into the flue gas condensate water storage tank.

[0097] According to the comparison result that the actual condensate temperature value is higher than or equal to the first preset condensate temperature value, the bypass control valve on the bypass pipeline is controlled to be closed, so that the flue gas condensate water flow passes through the wet cooling tower for secondary cooling, and the cooled flue gas condensate flows into the flue gas condensate water reservoir. The bypass control valve is controlled by the control device.

[0098] Furthermore, the cooling method also includes:

[0099] S201. Detect the ambient temperature.

[0100] S202: Compare the detected actual ambient temperature value with the preset ambient temperature value.

[0101] S203. Control the opening and closing states of the bypass control valve according to the comparison result.

[0102] In the present invention, by monitoring the ambient temperature, the system can automatically adjust the working mode according to the changes in external conditions, thereby enhancing the adaptability of the system. In different seasons or weather conditions, the system can optimize the cooling strategy according to the actual ambient temperature to ensure efficient operation in any environment.

[0103] In some embodiments, step S203 controls the opening and closing states of the bypass control valve according to the comparison results, including: according to the comparison result that the actual ambient temperature value is lower than the preset ambient temperature value, controlling the bypass control valve on the bypass pipe to open, so that the flue gas condensate water flow bypasses the wet cooling tower through the bypass pipe and flows into the flue gas condensate water storage tank.

[0104] According to the comparison result that the actual ambient temperature value is higher than or equal to the preset ambient temperature value, the bypass control valve on the bypass pipeline is controlled to close, so that the flue gas condensate water flows through the wet cooling tower for secondary cooling, and the cooled flue gas condensate flows into the flue gas condensate water storage tank. Among them, the bypass control valve is controlled by the control device.

[0105] In some embodiments, the cooling method further comprises:

[0106] S301. Detect the temperature of flue gas condensate after being cooled by an air-cooled heat exchanger.

[0107] S302: Compare the detected actual condensed water temperature value with the second preset condensed water temperature value.

[0108] S303. Control the opening and closing state of the recirculation control valve according to the comparison result.

[0109] In some embodiments, step S303 controls the opening and closing states of the recirculation control valve according to the comparison results, including: according to the comparison result that the actual condensed water temperature value is lower than the second preset condensed water temperature value, controlling the recirculation control valve on the recirculation pipeline to close, so that the flue gas condensed water flow continues to flow into the downstream pipeline.

[0110] According to the comparison result that the actual condensed water temperature is higher than or equal to the second preset condensed water temperature value, the recirculation control valve on the recirculation pipeline is controlled to open, so that the flue gas condensed water flow is circulated back to the air-cooled heat exchanger through the recirculation pipeline for circulation cooling. The recirculation control valve is controlled by the control device.

[0111] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A cooling system for flue gas condensate, characterized in that: The system comprises: A flue gas condensate collection pool, wherein the flue gas condensate collection pool is used to collect flue gas condensate; A flue gas condensate water reservoir, wherein the flue gas condensate water reservoir is used to store the flue gas condensate after cooling; A booster pump, the booster pump is used to pump the flue gas condensate in the flue gas condensate collection pool to the inlet of the air-cooled heat exchanger through a water supply pipeline; An air-cooled heat exchanger, the air-cooled heat exchanger is used to preliminarily cool the flue gas condensate, and the outlet of the air-cooled heat exchanger is connected to the inlet of the wet cooling tower through a water outlet pipeline; A wet cooling tower, the wet cooling tower is used to perform secondary cooling on the outlet water from the air-cooled heat exchanger, and the outlet of the wet cooling tower is connected to the flue gas condensate water reservoir through a water pipeline; A bypass pipeline, the bypass pipeline connecting the water outlet pipeline and the water delivery pipeline; a bypass control valve, the bypass control valve being arranged on the bypass pipeline and being electrically connected to the control device; and, A control device is used to control the opening and closing states of the bypass control valve according to preset conditions to control whether the outlet water of the air-cooled heat exchanger flows through the wet cooling tower for secondary cooling.

2. A cooling system for flue gas condensate water according to claim 1, characterized in that: The preset condition includes a temperature condition; the cooling system further includes a first temperature detection element, which is arranged at the outlet of the air-cooled heat exchanger and is electrically connected to the control device, and is used to detect the temperature of the flue gas condensate after being cooled by the air-cooled heat exchanger; Wherein, the control device controls the opening and closing state of the bypass control valve according to the comparison between the actual condensed water temperature value detected by the first temperature detection element and the first preset condensed water temperature value.

3. A cooling system for flue gas condensate water according to claim 1, characterized in that: The preset condition includes a temperature condition; the cooling system further includes a second temperature detection element, the second temperature detection element is electrically connected to the control device and is used to detect the ambient temperature; Wherein, the control device controls the opening and closing state of the bypass control valve according to the comparison between the actual ambient temperature value detected by the second temperature detection element and the preset ambient temperature value.

4. A cooling system for flue gas condensate water according to any one of claims 1 to 3, characterized in that: Also includes: A recirculation pipeline, the recirculation pipeline is connected to the water outlet pipeline and the flue gas condensate collection tank; A recirculation control valve, the recirculation control valve is electrically connected to the control device; wherein the control device is used to control the opening and closing states of the recirculation control valve according to preset conditions, so as to control whether the outlet water of the air-cooled heat exchanger flows through the air-cooled heat exchanger again for circulating cooling.

5. A cooling system for flue gas condensate water according to claim 4, characterized in that: The preset conditions include temperature conditions; when the first temperature detection element is provided at the outlet of the air-cooled heat exchanger, the control device controls the opening and closing state of the recirculation control valve based on the comparison between the actual condensed water temperature value detected by the first temperature detection element and the second preset condensed water temperature value.

6. A cooling system for flue gas condensate water according to any one of claims 1 to 3, characterized in that: There are two air-cooling heat exchangers, which are connected in parallel, and the inlets of the two air-cooling heat exchangers are respectively connected to the water supply pipeline, and the outlets of the two air-cooling heat exchangers are respectively connected to the water outlet pipeline.

7. A cooling system for flue gas condensate water according to claim 1, characterized in that: Also includes: A regulating valve is arranged in a pipeline at the inlet of the wet cooling tower and is electrically connected to the control device; wherein the control device controls the regulating valve to adjust the flow rate flowing into the wet cooling tower.

8. A method for cooling flue gas condensate, characterized in that: The method is implemented according to a cooling system for flue gas condensate water according to claim 2, comprising: Detecting the temperature of flue gas condensate after being cooled by the air-cooled heat exchanger; Comparing the detected actual condensed water temperature value with the first preset condensed water temperature value; The opening and closing states of the bypass control valve are controlled according to the comparison results.

9. A method for cooling flue gas condensate water according to claim 8, characterized in that: The step of controlling the opening and closing state of the bypass control valve according to the comparison result includes: According to the comparison result that the actual condensed water temperature value is lower than the first preset condensed water temperature value, the bypass control valve on the bypass pipeline is controlled to open, so that the flue gas condensed water flow bypasses the wet cooling tower through the bypass pipeline and flows into the flue gas condensed water storage tank; According to the comparison result that the actual condensate water temperature value is higher than or equal to the first preset condensate water temperature value, the bypass control valve on the bypass pipeline is controlled to close, so that the flue gas condensate water flow passes through the wet cooling tower for secondary cooling, and the cooled flue gas condensate flows into the flue gas condensate water reservoir.

10. A method for cooling flue gas condensate water according to claim 8, characterized in that: Also includes: Detect ambient temperature; Comparing the detected actual ambient temperature value with a preset ambient temperature value; The opening and closing states of the bypass control valve are controlled according to the comparison results.

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