Cooling system and method for flue gas condensate

Abstract

Embodiments of the present disclosure provide a cooling system and method for flue gas condensate, wherein the cooling system comprises: a flue gas condensate collection tank; a flue gas condensate storage tank used for storing cooled flue gas condensate; a booster pump used for pumping the flue gas condensate in the flue gas condensate collection tank to an inlet of an air-cooled heat exchanger by means of a water supply line; the air-cooled heat exchanger used for preliminarily cooling the flue gas condensate, wherein an outlet of the air-cooled heat exchanger is communicated with an inlet of a wet cooling tower by means of a water outlet line; the wet cooling tower used for performing secondary cooling on the condensate discharged from the air-cooled heat exchanger, wherein the outlet of the wet cooling tower is communicated with the flue gas condensate storage tank by means of a water delivery line; a bypass line communicated with the water outlet line and the water delivery line; a bypass control valve arranged on the bypass line and electrically connected to a control device; and the control device used for controlling open and closed states of the bypass control valve on the basis of a preset condition, so as to control whether the condensate discharged from the air-cooled heat exchanger flows through the wet cooling tower for secondary cooling.

Description

A cooling system and method for flue gas condensate Technical Field

[0001] The embodiments disclosed herein belong to the field of cooling equipment technology, specifically relating to a cooling system and method for flue gas condensate. Background Technology

[0002] The boiler-fed water intake device recovers moisture emitted into the atmosphere from the flue gas through heat exchange and cooling. Monitoring of the flue gas condensate shows that, except for pH, all other water quality indicators are better than those of urban reclaimed water, thus it can be considered a source for chemically treated water.

[0003] Because the temperature of flue gas condensate is in the range of 37.5 to 50°C, and the inlet water temperature of each membrane component and resin in the chemical water treatment system is required to be in the range of 22 to 28°C, flue gas condensate cannot be used directly as a water source for water treatment. It can only be used after being mixed with reclaimed water and cooled down.

[0004] 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 urgently needs to be solved by those skilled in the art. Summary of the Invention

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

[0006] A first aspect of the embodiments of this disclosure provides a cooling system for flue gas condensate, comprising:

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

[0008] A flue gas condensate storage tank is used to store flue gas condensate after cooling treatment.

[0009] A booster pump is used to pump the flue gas condensate in the flue gas condensate collection tank to the inlet of the air-cooled heat exchanger through a water delivery pipeline.

[0010] An air-cooled heat exchanger is used for preliminary cooling of 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 is used to perform secondary cooling on the effluent from the air-cooled heat exchanger, and the outlet of the wet cooling tower is connected to the flue gas condensate storage tank through a water supply pipeline.

[0012] A bypass pipeline, wherein the bypass pipeline connects the outlet pipeline and the water supply pipeline;

[0013] A bypass control valve, wherein the bypass control valve is disposed on the bypass pipeline and electrically connected to the control device; and...

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

[0015] Optionally, the preset conditions include temperature conditions; the cooling system further includes a first temperature detection element, which is disposed at the outlet of the air-cooled heat exchanger and electrically connected to the control device, for detecting the temperature of the flue gas condensate after being cooled by the air-cooled heat exchanger.

[0016] The control device controls the opening and closing state of the bypass control valve based on the comparison between the actual condensate temperature value detected by the first temperature detection element and the first preset condensate temperature value.

[0017] Optionally, the preset conditions include temperature conditions; 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.

[0018] The control device controls the opening and closing state of the bypass control valve based on 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, wherein the recirculation pipeline is connected to the outlet pipeline and the flue gas condensate collection tank;

[0021] A recirculation control valve is electrically connected to the control device; wherein the control device is used to control the opening and closing state of the recirculation control valve according to preset conditions, so as to control whether the water outlet 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 outlet of the air-cooled heat exchanger is equipped with the first temperature detection element, the control device controls the opening and closing state of the recirculation control valve based on the comparison between the actual condensate temperature value detected by the first temperature detection element and the second preset condensate temperature value.

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

[0024] Furthermore, it also includes:

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

[0026] A second aspect of the embodiments of this disclosure provides a cooling method for flue gas condensate, the method being implemented according to the above-described cooling system for flue gas condensate, comprising:

[0027] The temperature of the flue gas condensate after being cooled by the air-cooled heat exchanger is detected.

[0028] The actual condensate temperature value is compared with the first preset condensate temperature value;

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

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

[0031] Based on the comparison result that the actual condensate temperature value is lower than the first preset condensate temperature value, the bypass control valve on the bypass pipeline is controlled to open, so that the flue gas condensate flows through the bypass pipeline, bypassing the wet cooling tower and flowing into the flue gas condensate storage tank.

[0032] Based on 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 close, so that the flue gas condensate water flows through the wet cooling tower for secondary cooling, and the cooled flue gas condensate water flows into the flue gas condensate water storage tank.

[0033] Furthermore, it also includes:

[0034] Detect ambient temperature;

[0035] The detected actual ambient temperature value is compared with the preset ambient temperature value;

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

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

[0038] In this invention, an air-cooled heat exchanger can provide initial cooling for the flue gas condensate, effectively reducing its temperature. Furthermore, by connecting a wet cooling tower in series with the air-cooled heat exchanger, further cooling of the flue gas condensate flowing from the air-cooled heat exchanger outlet can be achieved. The control device determines whether secondary cooling is required for the flue gas condensate flowing from the air-cooled heat exchanger outlet based on preset conditions. This configuration ensures effective cooling of the flue gas condensate, enabling its recycling and utilization. It effectively alleviates the conflict between power generation and water conservation, and provides a feasible solution for maximizing water conservation in thermal power plants in water-scarce regions. Attached Figure Description

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

[0040] Figure 2 is a schematic flowchart of a cooling method for flue gas condensate according to an embodiment of the present disclosure.

[0041] In the diagram, 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 Implementation

[0042] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The detailed descriptions and accompanying drawings of the following embodiments are used to exemplarily illustrate the principles of this application, but should not be used to limit the scope of this application; that is, this application is not limited to the described embodiments. In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0044] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0045] As shown in Figure 1, a cooling system for flue gas condensate includes a flue gas condensate collection tank 1, a flue gas condensate storage tank 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 tank 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 treatment, and the booster pump 2 is used to pump the flue gas condensate in the flue gas condensate collection tank 1 to the inlet of the air-cooled heat exchanger 4 through the water supply pipeline 3.

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

[0048] The bypass control valve 10 is installed on the bypass pipeline 9 and is electrically connected to the control device. The control device is used to control the opening and closing state of the bypass control valve 10 according to preset conditions, so as 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 this invention, the air-cooled heat exchanger 4 can initially cool the flue gas condensate, effectively reducing its temperature. Furthermore, the wet cooling tower 6 is connected in series with the air-cooled heat exchanger 4, allowing for further cooling of the flue gas condensate flowing from the outlet of the air-cooled heat exchanger 4. The control device determines whether secondary cooling is needed for the flue gas condensate flowing from the outlet of the air-cooled heat exchanger 4 based on preset conditions. This configuration ensures effective cooling of the flue gas condensate, enabling its recycling and utilization. It effectively alleviates the conflict between power generation and water conservation, and provides a feasible solution for maximizing water conservation in thermal power plants in water-scarce regions.

[0050] The cooling system of the present invention can be applied to coal-fired power units in water-scarce areas of northern China and coal-fired power units in coastal areas where freshwater resources are scarce.

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

[0052] The control device controls the opening and closing states of the bypass control valve 10 by comparing the actual condensate temperature value detected by the first temperature detection element 11 with the first preset condensate temperature value.

[0053] In this invention, by installing 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 after preliminary cooling in real time. Based on the comparison between the actual condensate temperature and the preset temperature value, the control device can react quickly and dynamically adjust the state of the bypass control valve 10 to determine whether secondary cooling of the flue gas condensate is required.

[0054] When the actual condensate temperature is lower than the preset temperature threshold, the control system opens the bypass control valve 10 via the control device, allowing the flue gas condensate to flow through the bypass pipe 9, bypassing the wet cooling tower 6 and directly into the flue gas condensate storage tank 8, thus avoiding unnecessary secondary cooling and saving energy. If the actual condensate temperature is higher than or equal to the preset temperature threshold, the control system closes the bypass control valve 10 via the control device, allowing the water to flow through the wet cooling tower 6 for secondary cooling, ensuring the required cooling effect is achieved. Specifically, when the bypass control valve 10 is open, the resistance in the bypass pipe 9 is designed to be less than the resistance in the wet cooling tower 6 pipe, allowing the flue gas condensate to flow into the flue gas condensate storage tank 8 through the bypass pipe.

[0055] In some embodiments, the preset conditions include temperature conditions, and the cooling system further includes a second temperature detection element electrically connected to the control device for detecting ambient temperature.

[0056] The control device controls the opening and closing states of the bypass control valve 10 by comparing the actual ambient temperature value detected by the second temperature detection element with the preset ambient temperature value.

[0057] In this invention, by monitoring ambient temperature, the system can automatically adjust its operating mode according to changes in external conditions, enhancing its adaptability. Under different seasons or weather conditions, the system can optimize its cooling strategy based on the actual ambient temperature, ensuring efficient operation in any environment.

[0058] When the detected ambient temperature is low (below the preset ambient temperature value), the control system opens the bypass control valve 10 via the control device, allowing the flue gas condensate to flow through the bypass pipeline, bypassing the wet cooling tower 6 and directly into the flue gas condensate storage tank 8, thus 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 closes the bypass control valve 10 via the control device, allowing the flue gas condensate to flow through the wet cooling tower 6 for secondary cooling, ensuring the required cooling effect is achieved.

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

[0060] The recirculation pipeline 12 is connected to the outlet water pipeline 5 and the flue gas condensate collection tank 1. The recirculation control valve 13 is electrically connected to the control device. The control device is used to control the opening and closing state of the recirculation control valve 13 according to preset conditions, so as 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 via the control device. This allows the flue gas condensate to 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. Based on 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 optimal cooling performance under different operating conditions.

[0062] By intelligently controlling the recirculation process (achieved through a control device), the system can minimize energy consumption while ensuring cooling effectiveness and avoid unnecessary repeated cooling. The recirculation mechanism can fully utilize the cooling capacity of existing equipment, reduce reliance on additional cooling equipment, and improve overall energy efficiency.

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

[0064] In this 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 after preliminary cooling in real time, and accurately control the opening and closing state of the recirculation control valve 13 based on the comparison result of the actual temperature and the second preset temperature value.

[0065] When the actual condensate temperature is lower than the preset condensate temperature, the control device closes the recirculation control valve 13 on the recirculation pipeline 12, allowing the flue gas condensate to continue flowing into the downstream pipeline, thus avoiding unnecessary secondary cooling and saving energy. If the actual condensate temperature is higher than or equal to the preset condensate temperature, the control device opens the recirculation control valve 13 on the recirculation pipeline 12, allowing the flue gas condensate to circulate back to the air-cooled heat exchanger 4 for cooling, ensuring the required cooling effect is achieved. Specifically, when the recirculation control valve 13 is open, the resistance in the recirculation pipeline 12 is designed to be less than the resistance in the outlet pipeline 5, allowing the flue gas condensate to flow into the flue gas condensate collection tank 1 through the recirculation pipeline 12 and then circulate back to the air-cooled heat exchanger 4 for cooling via the booster pump 2.

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

[0067] In this invention, the two air-cooled heat exchangers 4 connected in parallel can simultaneously handle larger flow rates, improving the overall cooling capacity of the system and making it suitable for scenarios with high loads or large-scale cooling demands. Based on actual operating conditions, the control system can flexibly allocate the load between the two heat exchangers as needed, optimizing the cooling effect and avoiding overload of a single heat exchanger. The two parallel-connected air-cooled heat exchangers 4 provide redundancy; even if one heat exchanger fails or requires maintenance, the other can continue to operate, ensuring continuous system operation.

[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 electrically connected to a control device, wherein the control device controls the regulating valve 14 to regulate the flow rate into the wet cooling tower 6.

[0069] In this invention, the control device precisely controls the flow rate of the regulating valve 14 into the wet cooling tower 6 according to actual needs, ensuring that the wet cooling tower 6 always operates in the optimal working condition. The regulating valve 14 prevents the wet cooling tower 6 from overloading due to excessive flow or from failing to achieve a good 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 based on parameters such as temperature, pressure, or flow rate to regulate the flow rate 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 fog, which has a certain impact on the environment around the cooling tower. In particular, the white fog generated by the cooling tower in the winter in northern regions has a greater impact. In order to avoid the impact of the white fog generated by the wet cooling tower on the surrounding environment, a closed-loop dry-wet mixed operation cooling tower is adopted, which combines efficient cooling, white fog elimination and water-saving operation technologies.

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

[0073] In some embodiments, flue gas condensate is used as makeup water for the desulfurization system, while other production water uses reclaimed water. After the flue gas condensate is used for demineralized water preparation, the principle of water use is to use flue gas condensate entirely for chemical water treatment, with priority given to the use of flue gas condensate for desulfurization and other systems, and supplementing the shortfall with municipal wastewater.

[0074] Due to the significant increase in the utilization rate of flue gas condensate and the substantial reduction in the purchase of greywater, flue gas condensate can be supplied without the need for greywater replenishment during non-extreme weather conditions such as spring and autumn, thus meeting usage requirements.

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

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

[0077] The system is equipped with two booster pumps (2), two air-cooled heat exchangers (4, each with six air-cooled units), and one wet cooling tower (6), all installed outdoors. Each booster pump (2) is connected to a water supply pipeline (3) via piping. An electromagnetic flowmeter (15) is installed on the water supply pipeline (3) to monitor the flow rate. For corrosion and freeze protection, all flow-through components are made of 316L stainless steel, including but not limited to piping and valves. Furthermore, the cooling system includes a Roots blower to quickly drain any accumulated water from the flow-through components after the cooling system is shut down.

[0078] Each booster pump 2 is equipped with a reducing device 18 (as 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) Each air-cooled heat exchanger 4 is equipped with a reducing device 18 and a manual valve 20 (M) on the inlet and outlet pipes, respectively. The manual valve 20 is used for manual flow adjustment by the operator. Furthermore, a PE pump equipment 16 is installed on the outlet pipe 5 to propel the fluid through the outlet pipe 5, ensuring normal fluid flow within the cooling system.

[0079] A manual valve is installed on the recirculation line 12. The manual valve is located upstream of the recirculation control valve 13 and is used by the operator to manually control the flow rate in the recirculation line 12.

[0080] A manual valve is installed on the bypass pipeline 9, located upstream of the bypass control valve 10, for operators to manually control the flow rate within the bypass pipeline 9. The bypass pipeline 9 is connected to the water supply pipeline 7 via a reducing device.

[0081] The inlet and outlet pipes of the wet cooling tower 6 are equipped with manual valves. The manual valve of the inlet pipe 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 storage tanks 8. Each flue gas condensate storage tank 8 is connected to a water supply pipeline 7 through a pipeline. Each water supply pipeline 7 is equipped with a drive device (Motor abbreviation M), specifically a motor, which is used to drive the solenoid valve on the pipeline to regulate the flow rate of flue gas condensate into the flue gas condensate storage tank 8.

[0083] Air-cooled heat exchanger 4 is the main cooling equipment, and all high-temperature flue gas condensate undergoes preliminary cooling through it throughout the entire process. Each air-cooled unit of air-cooled heat exchanger 4 is equipped with a cooling fan below it. During operation, the flue gas condensate flows in through the inlet pipe at the top of the inlet chamber of the air-cooled unit, undergoes multiple cooling processes within the air-cooled heat exchanger 4, and finally flows out through the outlet pipe at the bottom of the outlet chamber, converging into the outlet pipe 5. The control device adjusts the number and frequency of the cooling fans based on the operating water volume and outlet water temperature.

[0084] The temperature of flue gas condensate is generally 37.5–50℃. The inlet water temperature for each membrane module and resin in the chemical water treatment system is required to be within the range of 22–28℃. The outlet temperature of the air-cooled heat exchanger 4 is detected by the first temperature sensing element 11 (also called a temperature element or temperature transmitter TE) and displayed by a temperature indicator TI. When the ambient temperature is consistently higher than 18℃ (the preset ambient temperature value) or the outlet water temperature of the air-cooled heat exchanger 4 is consistently higher than 25℃ (the first preset condensate temperature value), the outlet water from the air-cooled heat exchanger 4 needs to be connected in series with the wet cooling tower 6. Specifically, the control device, based on the comparison between the actual condensate temperature value or the actual ambient temperature value and the preset temperature, controls the bypass control valve 10 to close, allowing the outlet water from the air-cooled heat exchanger 4 to flow into the wet cooling tower 6 for secondary cooling. Conversely, the bypass control valve 10 is opened, allowing the outlet water of the air-cooled heat exchanger 4 to flow into the flue gas condensate storage tank 8.

[0085] When the outlet water temperature of the air-cooled heat exchanger 4 is higher than 30℃ (the second preset condensate temperature value), the control device controls the recirculation control valve 13 to open based on the comparison between the actual condensate temperature value detected and the preset temperature, so that the outlet water of the air-cooled heat exchanger 4 is circulated back to the flue gas condensate collection tank 1 for circulating cooling. Conversely, the bypass control valve 10 is closed, so that the outlet water of the air-cooled heat exchanger 4 flows downstream through the outlet pipe 5.

[0086] Water from the air-cooled heat exchanger 4 is sprayed from above the wet cooling tower 6, and after being evenly dispersed by the packing material, it is sprayed onto the water collection tray. At the same time, the fan of the wet cooling tower 6 blows air from bottom to top in the opposite direction to the water flow. The water film on the packing material comes into extensive contact with the cold air, and a mass and heat transfer process occurs, thereby reducing the temperature of the flue gas condensate.

[0087] High-temperature flue gas condensate, after being alkali-treated to adjust its quality, enters the flue gas condensate collection tank 1. It is then pumped by a booster pump 2 to the air-cooled heat exchanger 4 for cooling. Whether or not spray cooling is applied depends on the outlet water temperature; the specific decision-making logic is described above. If necessary, the condensate enters the wet cooling tower 6 through its inlet pipe and undergoes spray cooling (with the fan running). The cooled effluent then enters two flue gas condensate storage tanks 8. If not, it flows directly into the flue gas condensate storage tanks 8 through a bypass pipe.

[0088] In this invention, the cooling system described above enables the condensate recovered from the flue gas to be cooled and optimized for deep utilization, thereby improving the utilization rate of flue gas condensate, reducing production costs, and effectively reducing water consumption of coal-fired units. This achieves environmentally friendly and energy-saving operation of coal-fired units, creating significant water-saving, environmental, economic, and social benefits.

[0089] This invention effectively reduces the temperature of flue gas condensate, increases the utilization potential of flue gas condensate, and also reduces the amount of purchased reclaimed water, thus lowering power generation costs. Furthermore, it significantly reduces the risk of water shortages and potential disruptions to production operations caused by factors such as wastewater treatment plant capacity, equipment defects, and water usage by surrounding users. Simultaneously, it effectively controls problems arising from poor urban reclaimed water quality, which is highly susceptible to seasonal fluctuations, leading to short water production cycles, frequent defects, frequent chemical cleaning and regeneration operations, low equipment availability, and high maintenance workload in water treatment equipment.

[0090] Furthermore, the large-scale, widespread, and high-quality recycling and utilization of flue gas condensate reduces natural water consumption, creates favorable conditions for water resource protection, and effectively alleviates the conflict between power generation and water ecological protection. This provides a good example for maximizing water conservation in thermal power plants in water-scarce areas. It also effectively reduces water consumption in coal-fired units, achieving environmentally friendly and energy-saving operation. This contributes to practicing ecological civilization, pioneering a new path of clean energy and green ecological coordinated development, and promoting energy conservation, emission reduction, and efficiency improvement to a new level. It has broad application value for thermal power units in water-scarce areas.

[0091] Referring to FIG2, a second aspect of the embodiments of the present disclosure provides a cooling method for flue gas condensate, the method being implemented according to the above-described cooling system for flue gas condensate, comprising:

[0092] S101. Detect the temperature of the flue gas condensate after it has been cooled by the air-cooled heat exchanger.

[0093] S102. Compare the detected actual condensate temperature value with the first preset condensate temperature value.

[0094] S103. Control the opening and closing status of the bypass control valve based on the comparison results.

[0095] In this invention, by monitoring the temperature of the cooled flue gas condensate and comparing the actual condensate temperature with the preset temperature value, the control device can react 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, which controls the opening and closing state of the bypass control valve according to the comparison result, includes: 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 pipeline to open, so that the flue gas condensate water flows through the bypass pipeline, bypassing the wet cooling tower, and into the flue gas condensate water storage tank.

[0097] Based on the comparison result of the actual condensate temperature value being higher than or equal to the first preset condensate temperature value, the bypass control valve on the bypass pipeline is closed, allowing the flue gas condensate to flow through the wet cooling tower for secondary cooling, and the cooled flue gas condensate flows into the flue gas condensate storage tank. The bypass control valve is controlled by a control device.

[0098] Furthermore, cooling methods also include:

[0099] S201. Detect ambient temperature.

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

[0101] S203. Control the opening and closing status of the bypass control valve based on the comparison results.

[0102] In this invention, by monitoring ambient temperature, the system can automatically adjust its operating mode according to changes in external conditions, enhancing its adaptability. Under different seasons or weather conditions, the system can optimize its cooling strategy based on the actual ambient temperature, ensuring efficient operation in any environment.

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

[0104] Based on the comparison result of the actual ambient temperature value being higher than or equal to the preset ambient temperature value, the bypass control valve on the bypass pipeline is closed, allowing the flue gas condensate to flow through the wet cooling tower for secondary cooling, and the cooled flue gas condensate flows into the flue gas condensate storage tank. The bypass control valve is controlled by a control device.

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

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

[0107] S302. Compare the detected actual condensate temperature value with the second preset condensate temperature value.

[0108] S303. Control the opening and closing status of the recirculation control valve based on the comparison results.

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

[0110] Based on the comparison result of the actual condensate temperature being higher than or equal to the second preset condensate temperature value, the recirculation control valve on the recirculation pipeline is opened, allowing the flue gas condensate to circulate back to the air-cooled heat exchanger for cooling. The recirculation control valve is controlled by a control device.

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

Claims

1. A cooling system for flue gas condensate, characterized in that, The system includes: A flue gas condensate collection tank, wherein the flue gas condensate collection tank is used to collect flue gas condensate; A flue gas condensate storage tank is used to store flue gas condensate after cooling treatment. A booster pump is used to pump the flue gas condensate in the flue gas condensate collection tank to the inlet of the air-cooled heat exchanger through a water delivery pipeline. An air-cooled heat exchanger is used for preliminary cooling of 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 is used to perform secondary cooling on the effluent from the air-cooled heat exchanger, and the outlet of the wet cooling tower is connected to the flue gas condensate storage tank through a water supply pipeline. A bypass pipeline, wherein the bypass pipeline connects the outlet pipeline and the water supply pipeline; A bypass control valve, wherein the bypass control valve is disposed on the bypass pipeline and electrically connected to the control device; and... A control device is provided to control the opening and closing state of the bypass control valve according to preset conditions, so as to control whether the water outlet of the air-cooled heat exchanger flows through the wet cooling tower for secondary cooling.

2. A cooling system for flue gas condensate according to claim 1, characterized in that, The preset conditions include temperature conditions; the cooling system also includes a first temperature detection element, which is disposed at the outlet of the air-cooled heat exchanger and electrically connected to the control device, for detecting the temperature of flue gas condensate after being cooled by the air-cooled heat exchanger. The control device controls the opening and closing state of the bypass control valve based on the comparison between the actual condensate temperature value detected by the first temperature detection element and the first preset condensate temperature value.

3. A cooling system for flue gas condensate according to claim 1, characterized in that, The preset conditions include temperature conditions; the cooling system also includes a second temperature detection element, which is electrically connected to the control device and is used to detect the ambient temperature. The control device controls the opening and closing state of the bypass control valve based on 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 according to any one of claims 1-3, characterized in that, Also includes: A recirculation pipeline, wherein the recirculation pipeline is connected to the outlet pipeline and the flue gas condensate collection tank; A recirculation control valve is electrically connected to the control device; wherein the control device is used to control the opening and closing state of the recirculation control valve according to preset conditions, so as to control whether the water outlet 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 according to claim 4, characterized in that, The preset conditions include temperature conditions; when the outlet of the air-cooled heat exchanger is equipped with the first temperature detection element, the control device controls the opening and closing state of the recirculation control valve based on the comparison between the actual condensate temperature value detected by the first temperature detection element and the second preset condensate temperature value.

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

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

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

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

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

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