Cooling method of heat absorption tower and air-cooled heat absorption tower

Abstract

The present application relates to the technical field of photo-thermal power generation, and specifically discloses a cooling method of a heat absorption tower and an air-cooled heat absorption tower. The present application realizes the intelligent transformation from the traditional air cooling "constant air volume" to "on-demand air supply" through the intelligent control of temperature difference driving, and the system monitors in real time and fully utilizes the natural chimney effect. Only when the natural ventilation is insufficient, the fan starts to compensate, thereby minimizing the invalid operation time and power consumption of the fan, and significantly reducing the power station auxiliary power rate. At the same time, the closed-loop automatic control system based on real-time temperature difference feedback can accurately respond to the changes of power station load and environmental conditions, always providing stable and sufficient cooling air volume for the exhaust steam condensing, and ensuring the reliable operation of the cold end system. The high degree of automatic control reduces the complexity and uncertainty of manual intervention, and improves the intelligent management level and operation stability of the entire power station.

Description

Technical Field

[0001] This invention relates to the field of solar thermal power generation technology, specifically to a cooling method for a heat absorption tower and an air-cooled heat absorption tower. Background Technology

[0002] Tower solar thermal power plants are one of the mainstream solar thermal power generation technologies. Their cold-end systems generally employ direct or indirect air cooling technology to address the operational challenges in water-scarce regions. However, traditional freestanding air-cooled islands have revealed several inherent drawbacks in engineering practice:

[0003] Huge land area required: Traditional air-cooled islands consist of numerous parallel arrays of heat dissipation fins (cooling triangles), requiring a vast area of ​​land within the plant site for installation. This not only increases land acquisition costs but also limits the compact layout of the power plant. High civil engineering costs: To support the massive radiator array and guide airflow, large-scale, high-strength reinforced concrete support platforms and independent steel structure air ducts are needed. These civil engineering works are enormous, significantly increasing the initial investment cost of the project.

[0004] High energy consumption during operation: Independent air-cooled islands rely on large axial flow fan groups for forced ventilation, and these fans are typically driven by high-power asynchronous motors. The operation of these fan groups is one of the main sources of power consumption for the power plant. Especially in summer, when ambient temperatures are high and power generation loads are heavy, the fans need to operate at high frequency or even full load, which not only leads to a surge in power consumption but may also cause problems such as motor overcurrent, affecting system stability.

[0005] Severe noise pollution: The large number of fans operating at high speed at the same time generate huge aerodynamic noise, causing serious noise pollution to the factory boundary and surrounding environment, making it difficult to meet increasingly stringent environmental protection requirements.

[0006] Therefore, there is an urgent need for a cooling method and air-cooled heat absorption tower that can overcome the above-mentioned defects and achieve space-efficient, cost-saving, energy-optimized, and environmentally friendly heat absorption towers. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a cooling method and air-cooled heat absorption tower that is space-efficient, cost-saving, energy-optimized and environmentally friendly.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A cooling method for a heat-absorbing tower, the cooling method being applied to a heat-absorbing tower capable of ventilation cooling, comprising:

[0010] Obtain the effective temperature difference ΔT within the heat absorption tower duct;

[0011] Calculate the current natural wind speed contributed by the chimney effect based on the effective temperature difference ΔT. ;

[0012] Calculate the target wind speed required for complete condensation of exhaust steam. and natural wind speed By comparing the values, the wind speed difference V that needs to be compensated by the wind turbine is obtained. fan ;

[0013] Based on the wind speed difference V fan Controlling the fan frequency to generate a difference V between the fan frequency and the wind speed. fan The corresponding compensation air volume.

[0014] As a further improvement to the above technical solution:

[0015] The effective temperature difference ΔT satisfies the following relationship:

[0016] ΔT=T bottom -T top ;

[0017] Wherein: T bottom T represents the temperature of the air that enters the heat absorption tower duct and absorbs heat. top The temperature of the air at the outlet of the heat absorption tower duct.

[0018] As a further improvement to the above technical solution:

[0019] Calculate the current natural wind speed contributed by the chimney effect based on the effective temperature difference. The expression is as follows:

[0020] ;

[0021] in: Where g is the duct emission coefficient; g is the acceleration due to gravity. For effective chimney height.

[0022] As a further improvement to the above technical solution:

[0023] The target wind speed Calculated using the following formula:

[0024] ;

[0025] in: The mass flow rate of the exhaust steam; The latent heat of vaporization of exhaust steam at condensing pressure; The specific heat capacity of air at constant pressure; The density of air; The effective ventilation cross-sectional area of ​​the plane where the air-cooled radiator is located in the air duct;

[0026] The wind speed difference V fan Calculated using the following formula:

[0027] V fan =V req -V natural .

[0028] As a further improvement to the above technical solution:

[0029] The above is based on the wind speed difference V fan Controlling the fan frequency to generate a difference V between the fan frequency and the wind speed. fan The corresponding compensation air volume includes:

[0030] The calculated wind speed difference V fan As the input deviation, a PID control algorithm is used to calculate and generate a value similar to V. fan Corresponding output control signal It is used to control the fan frequency to generate the required compensating air volume;

[0031] The expression for the PID control algorithm is as follows:

[0032] ;

[0033] in: For proportional gain, deviation , The total wind speed actually measured by an anemometer, or by... = Calculation determined, The compensation wind speed generated by the fan is obtained by actual measurement in the duct or estimated based on the fan performance curve. This is the integral gain; This is the differential gain.

[0034] As a further improvement to the above technical solution:

[0035] The above is based on the wind speed difference V fan Controlling the fan frequency to generate a difference V between the fan frequency and the wind speed. fan The corresponding compensation air volume also includes:

[0036] when At that time, the wind speed difference needs to be compensated by the wind turbine. At this point, the fan speed will be reduced to a preset value or the fan will be completely stopped.

[0037] when At that time, the wind speed difference needs to be compensated by the wind turbine. At this point, the calculated As a goal, the frequency of the fan is adjusted through the PID control algorithm to make... and ensure total wind speed .

[0038] An air-cooled heat absorption tower is provided, which is cooled using the cooling method described above. The air-cooled heat absorption tower includes a heat absorption tower body.

[0039] The cylindrical wall of the heat absorption tower body and the partition wall and / or shear wall set inside the heat absorption tower body form a vertically rising air duct, and a fan and an air-cooled radiator are installed inside the air duct.

[0040] The fan is used to generate the compensating air volume required to completely condense the exhaust steam.

[0041] A lower temperature sensor is installed above the air-cooled radiator inside the air duct, and an upper temperature sensor is installed near the air outlet of the air duct.

[0042] The fan, upper temperature sensor, and lower temperature sensor are all electrically connected to the controller.

[0043] As a further improvement to the above technical solution:

[0044] The air-cooled radiator includes a waste steam header, a waste steam vacuum pipe, a waste steam tailpipe, a condensate pipe, a condensate main pipe, and a pumping system.

[0045] One end of the exhaust steam header is connected to the steam turbine, and the other end is connected to multiple sets of exhaust steam vacuum pipes; the exhaust steam vacuum pipes are arranged longitudinally along the air duct, and multiple sets of exhaust steam tailpipes are arranged at intervals on the exhaust steam vacuum pipes; the exhaust steam tailpipes are equipped with condensate pipes, and the condensate pipes are also connected to the condensate main pipe.

[0046] The pumping system is used to pump water from the condensate main pipe back into the steam turbine.

[0047] As a further improvement to the above technical solution:

[0048] The air inlet of the air duct is located at the bottom of the cylindrical wall of the heat absorption tower body, and the air outlet of the air duct is located at the top of the cylindrical wall of the heat absorption tower body.

[0049] The fan includes a booster fan and an induction fan, with the booster fan located inside the air inlet and the induction fan located inside the air outlet.

[0050] As a further improvement to the above technical solution:

[0051] Both the booster fan and the induced draft fan are axial flow fans whose speed is adjusted by a frequency converter.

[0052] Compared with the prior art, the advantages of the present invention are as follows:

[0053] (1) The method of this invention realizes the intelligent transformation from the traditional "constant air volume" of air cooling to "on-demand air supply" through temperature difference-driven intelligent control. The system monitors and makes full use of the natural chimney effect in real time. According to preliminary calculations, the effective ventilation volume contributed by the chimney effect can exceed 30% during the whole year of operation. The fan only starts to compensate when natural ventilation is insufficient, thereby minimizing the ineffective operation time and power consumption of the fan and significantly reducing the power plant's power consumption rate. At the same time, the closed-loop automatic control system based on real-time temperature difference feedback can accurately respond to changes in power plant load and environmental conditions, always providing a stable and sufficient cooling air volume for exhaust steam condensation, ensuring the reliable operation of the cold end system. The high degree of automation control reduces the complexity and uncertainty of manual intervention and improves the intelligent management level and operational stability of the entire power plant.

[0054] (2) This invention deeply integrates the air-cooling system with the heat-absorbing tower and adopts temperature difference-driven intelligent collaborative control, eliminating the additional land occupation requirement of the independent air-cooling island. Since the existing structure of the heat-absorbing tower is utilized, the high-cost independent support platform and air duct structure required for the air-cooling island are completely eliminated. Compared with the conventional air-cooling island, this part of the civil engineering cost can be saved by 100%, realizing the efficient use of land resources, greatly reducing or eliminating the civil engineering work of the support structure dedicated to the air-cooling system, reducing the initial investment, making full use of natural forces (chimney effect) and intelligent control, significantly reducing the energy consumption of the fan operation and the power plant power consumption rate, and using the heat-absorbing tower body as a natural sound barrier to effectively suppress and reduce the noise propagation of the system during operation.

[0055] (3) Since the fan of the air-cooled heat absorption tower of the present invention is integrated into the thick concrete cylinder wall, the tower body itself constitutes a huge natural sound barrier, which effectively prevents the fan operation noise from spreading to the outside of the factory boundary. It is expected that the noise value at the factory boundary can be stably controlled below 65dB(A), which can easily meet the environmental protection requirements. Attached Figure Description

[0056] Figure 1 This is a flowchart illustrating the cooling method of the heat absorption tower according to an embodiment of the present invention.

[0057] Figure 2 This is a schematic diagram of the structure of an air-cooled heat absorption tower according to an embodiment of the present invention;

[0058] Figure 3 This is a top view of the air-cooled heat absorption tower according to an embodiment of the present invention.

[0059] Legend:

[0060] 1. Heat absorber tower wall; 2. Molten salt pipe; 3. Shear wall; 4. Exhaust steam vacuum pipe; 5. Condensate pipe; 6. Heat sink; 7. Booster fan; 8. Induction fan; 9. Exhaust steam tailpipe; 10. Exhaust steam header; 11. Condensate main pipe; 12. Heat absorber; 13. Lower temperature sensor; 14. Upper temperature sensor; 15. Controller. Detailed Implementation

[0061] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] like Figure 1 As shown, this embodiment provides a cooling method for a heat-absorbing tower. The cooling method is applied to a heat-absorbing tower capable of ventilation cooling, and includes:

[0063] The ultimate control objective of this method is to ensure the total airflow velocity V through the radiator. total Always meet or slightly exceed a preset target flow rate V required for complete condensation of the exhaust steam. req The V req The value is dynamic and is usually determined by the power plant's current power generation load (i.e., exhaust steam flow), and is calibrated through prior experiments or simulation calculations.

[0064] Step 1: Obtain the effective temperature difference ΔT within the heat absorption tower duct, specifically:

[0065] The effective temperature difference ΔT satisfies the following relationship:

[0066] ΔT=T bottom -T top ;

[0067] Wherein: T bottom To monitor the temperature of the air entering the heat absorption tower duct and absorbing heat, one or more temperature sensors are installed approximately 1 meter above the air-cooled radiator array within the duct. According to relevant specifications, the temperature sensors should be installed in locations that reflect the average air temperature at that cross-section, avoiding dead zones in the airflow. The temperature measured at this point is the actual temperature of the ambient air after it has been heated by the exhaust steam radiator.

[0068] T top To measure the air temperature at the outlet of the heat absorption tower duct, another set or more temperature sensors are arranged in the area near the top outlet of the duct and the induced draft fan 8. This measuring point is used to measure the air temperature that is about to be discharged from the tower, and this temperature is approximately the ambient atmospheric temperature at that altitude.

[0069] The temperature sensors at the two measuring points continuously transmit the collected temperature data T in real time. bottom and T top Transmitted to controller 15.

[0070] Step 2: Chimney effect assessment. When air is heated, its density decreases, creating an upward buoyancy within a vertical duct—the chimney effect or thermal pressure-driven natural ventilation. The resulting natural wind speed V... natural The effective temperature difference ΔT is approximately proportional to the square root of the effective temperature difference ΔT. Controller 15 has this physical model or empirical formula built in, and calculates the current natural wind speed V contributed by the chimney effect based on the real-time calculated effective temperature difference ΔT. natural The current natural wind speed contributed by the chimney effect is estimated based on the effective temperature difference ΔT. Specifically:

[0071] The natural wind speed Vnatural generated by natural ventilation driven by the chimney effect or thermal pressure is approximately proportional to the square root of the effective temperature difference ΔT. The current natural wind speed contributed by the chimney effect is calculated based on the effective temperature difference. The expression is as follows:

[0072] ;

[0073] in: is the duct emission coefficient, a dimensionless constant, typically ranging from 0.6 to 0.7. The specific value depends on the geometry of the duct inlet and outlet and the friction resistance, and can be determined through CFD (Computational Fluid Dynamics) simulation or experimental calibration; g is the acceleration due to gravity, approximately 9.81 m / s². For effective chimney height, In this embodiment, Defined as the vertical distance from the vertical center of the heat exchange core of the air-cooled radiator to the air outlet of the air duct, this height is the effective height for generating thermal pressure difference.

[0074] Step 3: Wind speed difference calculation: Calculate the target wind speed required for complete condensation of the exhaust steam and compare it with the natural wind speed to obtain the wind speed difference that needs to be compensated by the fan. Specifically:

[0075] The target wind speed Calculated using the following formula:

[0076] ;

[0077] in: This is the mass flow rate of the exhaust steam (kg / s), which is directly related to the real-time generating load P_load (MW) of the power plant. Typically, This functional relationship is determined by the thermodynamic performance curve of the steam turbine (usually provided by the manufacturer) and can be regarded as a known input parameter in actual operation; The latent heat of vaporization of the exhaust steam at the condensing pressure (J / kg) is a thermodynamic property parameter that depends mainly on the condensing temperature and pressure of the exhaust steam and can be found in the standard saturated steam table. The specific heat capacity of air at constant pressure is approximately 1005 J / (kg·K); This is the density of air (kg / m³), and its value is affected by temperature and altitude, and can be calculated based on real-time temperature. The effective ventilation cross-sectional area (m²) of the plane where the air-cooled radiator is located in the air duct;

[0078] The wind speed difference V fan Calculated using the following formula:

[0079] V fan =V req -V natural .

[0080] Step 4: Based on the wind speed difference V fan Controlling the fan frequency to generate a difference V between the fan frequency and the wind speed. fan The corresponding compensation air volume is as follows:

[0081] The calculated wind speed difference V fan As the input deviation, a PID control algorithm is used to calculate and generate a value similar to V. fan Corresponding output control signal The frequency of the inverter used to control the frequency of the fan is used to enable the fan to generate the required compensation air volume. The fan preferably includes two sets: a booster fan and an induction fan, which can form a larger and stronger airflow, making it easier to accurately control the frequency to provide compensation air volume. The compensation air volume is the sum of the booster fan and the induction fan.

[0082] The expression for the PID control algorithm is as follows:

[0083] ;

[0084] in: For the proportional stage, For proportional gain, deviation , The total wind speed actually measured by an anemometer, or by... = The calculations show that the greater the deviation, the stronger the adjustment force, and the faster the response to system changes.

[0085] Preferably, in one embodiment, The compensation wind speed generated by the booster fan 7 and the induced fan 8 is obtained by actual measurement in the duct or by estimation based on the fan performance curve. This is the integration term, which accumulates past deviations. As long as a deviation exists, the integral term will continue to increase or decrease until the deviation reaches zero. Its main function is to eliminate steady-state errors and ensure that, during long-term stable operation, the actual total wind speed is precisely equal to the target wind speed. This is crucial for maintaining stable exhaust back pressure. This is the integral gain; For the differential element, The differential gain represents the rate of change of the response deviation. It can predict the future trend of the deviation and provide a damping or accelerating effect when the deviation changes drastically, thereby suppressing system oscillations and improving the dynamic stability and response speed of the system, especially during periods of negative power generation or sudden changes in environmental wind.

[0086] Preferably, both the booster fan 7 and the induced draft fan 8 are axial flow fans whose speed is adjusted by a frequency converter.

[0087] In one embodiment, the inverter is controlled as follows:

[0088] Inverter command issuance: This control signal is usually a standard 4-20mA analog signal or digital communication signal, which is sent to the inverters of booster fan 7 and induced fan 8.

[0089] Dynamic frequency adjustment: The frequency converter adjusts the operating frequency of the fan motor in real time and smoothly based on the received control signal, thereby precisely controlling the fan speed, generating the required compensating air volume, and ensuring... + ≈ .

[0090] The frequency converter adjusts the operating frequency of the fan motor smoothly and in real time based on the received control signals, thereby precisely controlling the fan speed to generate the required compensating air volume and ensure... The equation means that the ultimate goal of the entire control system is to adjust the fan so that the sum of the natural wind speed contributed by the chimney effect and the compensated wind speed actually contributed by the fan can dynamically and accurately approach and maintain the total target wind speed required under the current operating conditions. Due to system inertia and measurement errors, the perfect equality is instantaneous. The task of the control system is to minimize the difference between the two (i.e., steady-state error) within the allowable range.

[0091] Controlling the fan frequency also includes two typical operating conditions and coordinated operation modes, specifically:

[0092] Operating Condition 1: Natural Ventilation Dominant Operating Condition

[0093] Triggering condition: When the controller 15 calculates in real time... At this point, the system enters the primary natural ventilation mode. This trigger condition means that the natural wind speed generated solely by the chimney effect is sufficient or even exceeds the target wind speed required for complete condensation of the exhaust steam under the current load. At this time, the wind speed difference needs to be compensated by the fan. ;

[0094] Typical scenario: This usually occurs when the power plant is operating at high load (high exhaust steam flow, leading to...) High temperatures, winter, or periods of large diurnal temperature variation (ambient temperature) These factors, including low effective temperature difference (ΔT) and high chimney effect, collectively lead to a large effective temperature difference (ΔT) and a strong chimney effect. While there is no fixed threshold for ΔT, experimental studies show that natural ventilation capacity increases significantly when the effective temperature difference exceeds a certain value.

[0095] Control strategy: The controller 15 outputs commands to reduce the frequency of the booster fan 7 and the induced draft fan 8 inverters to an extremely low preset value (e.g., the minimum speed just to maintain bearing lubrication or prevent backflow of airflow), and in some cases the fans can even stop running completely, thereby achieving maximum energy saving.

[0096] Operating Condition 2: Forced-Natural Coordinated Ventilation

[0097] Triggering condition: When the controller 15 calculates in real time... At this point, the system enters a forced-natural coordinated ventilation mode. This trigger condition indicates that natural ventilation is insufficient to meet the heat dissipation requirements, and the fans must be activated to compensate. At this time, the difference in air velocity that needs to be compensated by the fans... ;

[0098] Typical scenario: This usually occurs when the power plant is operating at low load, the ambient temperature is high (especially during the day in summer), or the weather is cloudy or windless. These factors result in a smaller ΔT and a weaker chimney effect.

[0099] Control strategy: Controller 15 calculates... The objective is to precisely adjust the frequencies of the booster fan 7 and the induced fan 8 using the PID control algorithm, so that they generate... Compensation wind speed to ensure total wind speed Stable at Nearby, forced ventilation is used to compensate for insufficient airflow and ensure effective condensation of exhaust steam.

[0100] Coordinated control: Throughout the adjustment process, the controller 15 coordinates the operating frequency and power ratio of the booster fan 7 and the induction fan 8 to form a stable and efficient vertical air column and avoid airflow turbulence.

[0101] The heat-absorbing tower cooling method in this embodiment utilizes temperature difference-driven intelligent control, leveraging the advantages of integrating the heat-absorbing tower with the air-cooling system. It coordinates natural ventilation cooling with forced fan cooling, achieving an intelligent transformation from the traditional "constant airflow" of air cooling to "on-demand air supply." The system monitors and fully utilizes the natural chimney effect in real time. Preliminary calculations indicate that the effective ventilation contributed by the chimney effect can exceed 30% during year-round operation. The fan only activates to compensate when natural ventilation is insufficient, thereby minimizing the ineffective operating time and power consumption of the fan, significantly reducing the power plant's power consumption rate. Simultaneously, the closed-loop automatic control system based on real-time temperature difference feedback can accurately respond to changes in power plant load and environmental conditions, consistently providing a stable and sufficient cooling airflow for exhaust steam condensation, ensuring the reliable operation of the cold-end system. This high degree of automation reduces the complexity and uncertainty of manual intervention, improving the overall intelligent management level and operational stability of the power plant.

[0102] like Figures 2 to 3 As shown, this embodiment also provides an air-cooled heat absorption tower, which is cooled using the cooling method described above. The air-cooled heat absorption tower includes a heat absorption tower body.

[0103] The cylindrical wall of the heat absorption tower body and the partition wall and / or shear wall 3 set inside the heat absorption tower body form a vertically rising air duct. A fan and an air-cooled radiator are provided in the air duct. Preferably, a booster fan 7, an air-cooled radiator and an induced fan 8 are arranged in sequence along the direction from the air inlet to the air outlet in the air duct.

[0104] The absorber 12 of the heat absorption tower is located at the top of the heat absorption tower and is connected to the molten salt pipe 2, which is also located inside the air duct.

[0105] The booster fan 7 and the induced fan 8 are used to generate the compensating air volume required to completely condense the exhaust steam.

[0106] A lower temperature sensor 13 is installed above the air-cooled radiator inside the air duct, and an upper temperature sensor 14 is installed near the air outlet of the air duct.

[0107] The booster fan 7, the induced draft fan 8, the upper temperature sensor 14, and the lower temperature sensor 13 are all electrically connected to the controller 15.

[0108] In the aforementioned air-cooled heat absorption tower, the construction and integration of a vertical air duct are achieved: This embodiment cleverly utilizes the tower's own architectural structure. The heat absorption tower is typically a tall, reinforced concrete main structure. The concrete cylinder wall of the tower serves as the outer enclosure, and existing shear walls 3 or additional partition walls within the tower can be used to jointly enclose and form a vertical, continuous upward air duct. The lower part of this duct is the air inlet, and the upper part is the air outlet, constituting the core airflow channel required for air cooling, eliminating the need for a separate independent duct. Efficient arrangement of the cooling equipment: The air-cooled radiator unit for exhaust steam condensation is arranged at the bottom of the air duct, typically at a height of approximately 15-20 meters above the ground. After being discharged from the turbine, the exhaust steam is transported through pipes to the radiator header here and flows within the tube bundle. This arrangement allows the cooling air entering from below to flow vertically upwards through the radiator for efficient heat exchange. Dual-layer variable frequency fan system layout: To ensure sufficient cooling airflow under all operating conditions, this system employs a dual-layer fan system, with all fans being variable frequency fans whose speed can be adjusted via a frequency converter. Booster fan 7: Multiple air inlets are opened at the lower part of the heat absorption tower wall 1, near ground level, and axial flow booster fans 7 are installed at these inlets. Their function is to force ambient air into the bottom of the vertical duct when natural ventilation is insufficient. Induction fan 8: Induction fans 8 are installed on the top outlet area of ​​the vertical duct (typically at a height of no less than 150 meters above the ground) on the tower wall. Their function is to enhance the suction effect at the top of the duct when needed, ensuring smooth airflow discharge.

[0109] The air-cooled heat absorption tower in this embodiment deeply integrates the air-cooling system with the heat absorption tower and adopts an integrated photothermal air-cooling system with temperature difference-driven intelligent collaborative control. This eliminates the additional land occupation requirement of a separate air-cooling island, realizes efficient use of land resources, significantly reduces or eliminates the amount of civil engineering work for the dedicated support structure of the air-cooling system, reduces initial investment, makes full use of natural forces (chimney effect) and intelligent control, significantly reduces the energy consumption of the wind turbine and the power plant's power consumption rate, and uses the heat absorption tower body as a natural sound barrier to effectively suppress and reduce the outward propagation of noise during system operation.

[0110] The air-cooled radiator includes a waste steam header 10, a waste steam vacuum pipe 4, a waste steam tail pipe 9, a condensate pipe 5, a condensate main pipe 11, and a pumping system.

[0111] One end of the exhaust steam header 10 is connected to the steam turbine, and the other end is connected to multiple sets of exhaust steam vacuum pipes 4; the exhaust steam vacuum pipes 4 are arranged longitudinally along the air duct, and multiple sets of exhaust steam tail pipes 9 are arranged at intervals on the exhaust steam vacuum pipes 4; the exhaust steam tail pipes 9 are provided with condensate pipes 5, and the condensate pipes 5 are also connected to the condensate main pipe 11.

[0112] The exhaust steam tailpipe 9 is also equipped with heat sinks 6 to accelerate heat dissipation.

[0113] The pumping system is used to pump water from the condensate main pipe 11 back into the steam turbine.

[0114] The air inlet of the air duct is located at the bottom of the cylindrical wall 1 of the main body of the heat absorption tower, and the air outlet of the air duct is located at the top of the cylindrical wall of the main body of the heat absorption tower.

[0115] The booster fan 7 is installed inside the air inlet, and the induced draft fan 8 is installed inside the air outlet.

[0116] Both the booster fan 7 and the induced draft fan 8 are axial flow fans whose speed can be adjusted by a frequency converter.

[0117] The above description is merely a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and modifications obtained without departing from the inventive concept should also be considered within the scope of protection of the present invention.

Claims

1. A cooling method for a heat-absorbing tower, said cooling method being applied to a heat-absorbing tower capable of ventilation cooling, characterized in that, include: Obtain the effective temperature difference ΔT within the heat absorption tower duct; Calculate the current natural wind speed contributed by the chimney effect based on the effective temperature difference ΔT. ; Calculate the target wind speed required for complete condensation of exhaust steam. and natural wind speed By comparing the values, the wind speed difference V that needs to be compensated by the wind turbine is obtained. fan ; Based on the wind speed difference V fan Controlling the fan frequency to generate a difference V between the fan frequency and the wind speed. fan The corresponding compensation air volume; The effective temperature difference ΔT satisfies the following relationship: ΔT=T bottom -T top ; Wherein: T bottom T represents the temperature of the air that enters the heat absorption tower duct and absorbs heat. top The temperature of the air at the outlet of the heat absorption tower duct; Calculate the current natural wind speed contributed by the chimney effect based on the effective temperature difference. The expression is as follows: ； in: Where g is the duct emission coefficient; g is the acceleration due to gravity. Effective chimney height; The target wind speed Calculated using the following formula: ； in: The mass flow rate of the exhaust steam; The latent heat of vaporization of exhaust steam at condensing pressure; The specific heat capacity of air at constant pressure; The density of air; The effective ventilation cross-sectional area of ​​the plane where the air-cooled radiator is located in the air duct; The wind speed difference V fan Calculated using the following formula: V fan =V req -V natural 。 2. The cooling method for a heat absorption tower according to claim 1, characterized in that, The above is based on the wind speed difference V fan Controlling the fan frequency to generate a difference V between the fan frequency and the wind speed. fan The corresponding compensation air volume includes: The calculated wind speed difference V fan As the input deviation, a PID control algorithm is used to calculate and generate a value similar to V. fan Corresponding output control signal It is used to control the fan frequency to generate the required compensating air volume; The expression for the PID control algorithm is as follows: ； in: For proportional gain, deviation , The total wind speed actually measured by an anemometer, or by... = Calculation determined, The compensation wind speed generated by the fan is obtained by actual measurement in the duct or estimated based on the fan performance curve. This is the integral gain; This is the differential gain.

3. The cooling method for a heat absorption tower according to claim 2, characterized in that, The above is based on the wind speed difference V fan Controlling the fan frequency to generate a difference V between the fan frequency and the wind speed. fan The corresponding compensation air volume also includes: when At that time, the wind speed difference needs to be compensated by the wind turbine. At this point, the fan speed will be reduced to a preset value or the fan will be completely stopped. when At that time, the wind speed difference needs to be compensated by the wind turbine. At this point, the calculated As a goal, the frequency of the fan is adjusted through the PID control algorithm to make... and ensure total wind speed .

4. An air-cooled heat absorption tower, characterized in that, The air-cooled heat absorption tower is cooled by any one of the cooling methods described in claims 1-3, and the heat absorption tower includes a heat absorption tower body; The cylindrical wall of the heat absorption tower body and the partition wall and / or shear wall set inside the heat absorption tower body form a vertically rising air duct, and a fan and an air-cooled radiator are installed inside the air duct. The fan is used to generate the compensating air volume required to completely condense the exhaust steam. A lower temperature sensor is installed above the air-cooled radiator inside the air duct, and an upper temperature sensor is installed near the air outlet of the air duct. The fan, upper temperature sensor, and lower temperature sensor are all electrically connected to the controller.

5. An air-cooled heat absorption tower according to claim 4, characterized in that, The air-cooled radiator includes a waste steam header, a waste steam vacuum pipe, a waste steam tailpipe, a condensate pipe, a condensate main pipe, and a pumping system. One end of the exhaust steam header is connected to the steam turbine, and the other end is connected to multiple sets of exhaust steam vacuum pipes; the exhaust steam vacuum pipes are arranged longitudinally along the air duct, and multiple sets of exhaust steam tailpipes are arranged at intervals on the exhaust steam vacuum pipes; the exhaust steam tailpipes are equipped with condensate pipes, and the condensate pipes are also connected to the condensate main pipe. The pumping system is used to pump water from the condensate main pipe back into the steam turbine.

6. An air-cooled heat absorption tower according to claim 4, characterized in that, The air inlet of the air duct is located at the bottom of the cylindrical wall of the heat absorption tower body, and the air outlet of the air duct is located at the top of the cylindrical wall of the heat absorption tower body. The fan includes a booster fan and an induction fan, with the booster fan located inside the air inlet and the induction fan located inside the air outlet.

7. An air-cooled heat absorption tower according to claim 6, characterized in that, Both the booster fan and the induced draft fan are axial flow fans whose speed is adjusted by a frequency converter.

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