Circulating water potential energy recovery device

Abstract

The present disclosure relates to a circulating water potential energy recovery device, comprising: a cooling tower body, a water spraying filler is arranged inside the upper part of the cooling tower body, and a water collecting pool is arranged at the bottom end of the cooling tower body; a water collecting tank is arranged inside the cooling tower body and between the water spraying filler and the water collecting pool; a water turbine, the water inlet end of the water turbine is communicated with the water outlet end of the water collecting tank; a plurality of fans are arranged uniformly along the inner wall or the outer wall of the cooling tower body; a variable speed transmission mechanism is drivingly connected between the water turbine and the fan; and a control mechanism is electrically connected with the water turbine and the fan respectively. In this way, the device fully recycles the potential energy of the fall of the circulating water of the power plant cooling tower, directly drives the fan to operate through the water turbine and the variable speed transmission mechanism, replaces the traditional motor driving mode, greatly reduces the power consumption of the mechanical tower fan, and has a remarkable energy saving effect.

Description

Technical Field

[0001] This disclosure relates to the field of energy-saving technology for industrial cooling systems, and more specifically, to a circulating water potential energy recovery device. Background Technology

[0002] In the circulating water system of a thermal power plant, the mechanical draft cooling tower is a key piece of equipment to ensure the safe and economical operation of the unit. Its working principle is as follows: the high-temperature circulating water after heat exchange in the condenser is evenly sprayed onto the water-spraying packing through the water distribution system, and flows downward under the action of gravity, exchanging heat with the cold air flowing upward; the cooled circulating water falls into the water collection pool at the bottom of the tower, and is then transported back to the condenser for reuse by the circulating water pump.

[0003] Existing mechanical cooling towers generally use large top-mounted electric fans to provide cooling air. The fans are directly driven by electric motors through reducers, resulting in high energy consumption. A few utilize the surplus pressure of the circulating water system to drive a water turbine that drives the fan. However, the water turbine is mostly connected in series in the main circulating water circuit, only utilizing the residual pressure energy provided by the water pump, and does not recover the gravitational potential energy released by the circulating water as it falls inside the cooling tower.

[0004] In reality, the circulating water experiences a drop of 5m to 10m from the spray packing material to the collection tank, containing a significant amount of recoverable potential energy. For example, in a medium-sized power plant, the circulating water volume can reach tens of thousands of tons per hour, with a potential power output of hundreds of kilowatts. Currently, this energy is entirely dissipated through the impact of the falling water and turbulence, resulting in energy waste, accounting for approximately 5% to 10% of the total energy consumption of the cooling system, and directly increasing the power plant's stationary power consumption rate.

[0005] Meanwhile, the airflow distribution formed by a single large fan at the top of a traditional tower is uneven, and dead zones of airflow are easily formed near the tower wall and in areas far from the axis, resulting in insufficient heat exchange between the water and the air, leading to higher outlet water temperatures and limited cooling efficiency. In addition, large fans and their supporting transmission mechanisms have complex structures, are difficult to install and maintain, and have a high risk of single-point failures. Once they stop, they will directly affect the cooling capacity of the entire tower, resulting in poor operational reliability. Summary of the Invention

[0006] The purpose of this disclosure is to provide a circulating water potential energy recovery device to at least partially solve the problems existing in the related art.

[0007] To achieve the above objectives, this disclosure provides a circulating water potential energy recovery device, comprising: The cooling tower body has water-spraying packing material arranged on the upper part of the cooling tower body, and a water collection pool is provided at the bottom of the cooling tower body; A water collection tank is installed inside the cooling tower body and located between the water spray packing and the water collection pool; A water turbine, wherein the water inlet of the water turbine is connected to the water outlet of the water collection tank; Multiple fans are evenly arranged along the circumference of the inner or outer wall of the cooling tower. A variable speed transmission mechanism is connected between the water turbine and the wind turbine; and The control mechanism is electrically connected to the water turbine and the wind turbine, respectively.

[0008] In some possible implementations, the water collection tank is constructed in a conical shape, and the tank wall is arranged to slope downward from the side wall of the cooling tower to the central axis.

[0009] In some possible implementations, the inner wall of the water collection tank is provided with guide fins.

[0010] In some possible implementations, the water turbine is an impulse water turbine, which includes an inlet pipe, a nozzle, a runner, and a housing. The upper end of the inlet pipe is connected to the outlet end of the water collection tank, and the lower end of the inlet pipe is fixedly connected to the nozzle. The runner is rotatably installed inside the housing, and the nozzle is located directly above the runner.

[0011] In some possible implementations, the turbine is a double-impact turbine, and the runner is a hollow through-type structure.

[0012] In some possible implementations, the outer circumference of the rotor is uniformly provided with multiple blades, the upper part of which is a straight section and the lower part is a curved section.

[0013] In some possible implementations, the outer surface of the blade is provided with a tungsten carbide coating.

[0014] In some possible implementations, the transmission mechanism includes a speed increaser, an overrunning clutch, and an electromagnetic clutch connected in sequence. The input shaft of the speed increaser is connected to the shaft of the water turbine, and the output end of the electromagnetic clutch is connected to the wind turbine.

[0015] In some possible implementations, the speed increaser is a planetary gear speed increaser.

[0016] In some possible implementations, the circulating water potential energy recovery device further includes a water flow sensor installed at the turbine inlet, a wind speed sensor installed at the fan outlet, and a water temperature sensor installed inside the water collection tank.

[0017] Through the above technical solution, this device fully recovers and utilizes the potential energy of the cooling tower's circulating water. A water turbine, in conjunction with a variable-speed transmission mechanism, directly drives the fan, replacing the traditional motor-driven method. This significantly reduces the power consumption of the cooling tower fan, resulting in substantial energy savings. Furthermore, the device leverages the existing cooling tower structure, resulting in a compact layout, minimal modification difficulty, and strong adaptability. Combined with independent electrical control and monitoring, it ensures long-term stable and reliable operation, effectively reducing unit maintenance costs and plant power consumption.

[0018] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a circulating water potential energy recovery device provided in an exemplary embodiment of the present disclosure.

[0020] Explanation of reference numerals in the attached figures 1-Cooling tower body; 2-Water spraying packing; 3-Water collection pool; 4-Water collection trough; 5-Water turbine; 6-Fan; 7-Speed ​​transmission mechanism; 71-Increaser; 72-Electromagnetic clutch; 8-Control mechanism. Detailed Implementation

[0021] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0022] In this disclosure, unless otherwise stated, the directional terms "upper," "lower," "top," and "bottom" are defined based on the actual direction in which the relevant components are used. "Inner" and "outer" refer to the contours of the corresponding parts themselves. The terms "first," "second," etc., are used to distinguish different components and do not indicate sequence or importance. In this disclosure, when the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0023] Reference Figure 1This disclosure provides a circulating water potential energy recovery device for use in power plant turbine tower fans. The device includes a cooling tower body 1, a water collection tank 4, a water turbine 5, multiple fans 6, a speed transmission mechanism 7, and a control mechanism 8. The cooling tower body 1 has a water-spraying packing material 2 arranged at its upper part, and a water collection pool 3 at its bottom. The water collection tank 4 is located inside the cooling tower body 1, between the water-spraying packing material 2 and the water collection pool 3, and is used to collect the circulating water falling from the cooling tower body 1. The water inlet of the water turbine 5 is connected to the water outlet of the water collection tank 4, allowing it to utilize the potential energy difference of the circulating water to output power. Multiple fans 6 are evenly arranged circumferentially along the inner or outer wall of the cooling tower body 1. The speed transmission mechanism 7 is connected between the water turbine 5 and the fans 6 to transmit the power of the water turbine 5 to the fans 6. The control mechanism 8 is electrically connected to the water turbine 5 and the fans 6 respectively, and is used to monitor and control the overall operating status of the unit.

[0024] It should be noted that the fan arrangement method disclosed herein is not limited to the aforementioned distributed fan structure. It can also be a horizontal annular air duct scheme. Specifically, an annular air duct structure can be constructed around the cooling tower basin, with a ring of air outlets evenly opened on the inner side of the air duct. Each distributed fan uniformly supplies air into the annular air duct, and then the airflow is evenly delivered into the tower through each air outlet of the air duct, further homogenizing the flow field distribution inside the tower and improving cooling uniformity. Alternatively, it can be a jet-induced scheme, which can utilize the water potential energy recovered by the device to drive an air compressor to generate high-pressure airflow, which is then ejected at high speed through jet nozzles arranged around the tower. The Coanda effect is used to induce a large amount of outside air to enter the cooling tower to achieve ventilation and heat exchange. This scheme has no rotating moving parts, the equipment has high operational reliability and low maintenance, and can achieve the function of ventilation and cooling of the cooling tower.

[0025] Through the above technical solution, this device fully recovers and utilizes the potential energy of the cooling tower's circulating water. The water turbine 5, in conjunction with the variable speed transmission mechanism 7, directly drives the fan 6, replacing the traditional motor drive method. This significantly reduces the power consumption of the cooling tower fan, resulting in remarkable energy savings. Furthermore, the device leverages the existing cooling tower structure, resulting in a compact layout, minimal modification difficulty, and strong adaptability. Combined with independent electrical control and monitoring, it ensures long-term stable and reliable operation, effectively reducing unit maintenance costs and plant power consumption.

[0026] Among them, reference Figure 1 The water collection tank 4 can be constructed in a conical shape, with the tank wall sloping downwards from the side wall of the cooling tower body 1 to the central axis. By adopting a conical structure that is wider at the top and narrower at the bottom, combined with the sloping tank wall, the water receiving range can be greatly expanded, which can fully receive the dispersed water flow falling from the water spraying packing 2, and orderly gather the large area of ​​scattered unpressurized circulating water to the bottom outlet of the water collection tank 4, effectively concentrating the water potential energy, avoiding water flow overflow and loss, and improving the concentration of water flow and the utilization rate of water potential energy.

[0027] Furthermore, the inner wall of the water collection tank 4 can be equipped with guide fins. By adding guide fins, the gravity-fed water collected in the tank can be further regulated and guided, constraining the water flow trajectory and effectively suppressing turbulence, eddies, and chaotic flow phenomena generated during the water collection process, reducing kinetic energy loss and turbulent energy loss inside the water body. At the same time, the guide fins can guide the water flow smoothly and orderly towards the bottom outlet of the water collection tank 4, further improving the water flow collection effect and the uniformity of the outlet, ensuring a stable jet velocity and regular flow pattern entering the turbine 5, maximizing the utilization of the circulating water's head difference potential energy, continuously improving the turbine's energy conversion efficiency, and ensuring the stable and efficient operation of the potential energy recovery device.

[0028] In some embodiments, refer to Figure 1 The water turbine 5 can be an impulse turbine, suitable for the atmospheric pressure conditions of gravity-fed cooling tower water, and can effectively recover the potential energy of the circulating water's fall. Specifically, the water turbine 5 can include an inlet pipe, a nozzle, a runner, and a housing. The upper end of the inlet pipe is connected to the outlet of the water collection tank 4, which can stably receive the water flow that has been collected and regulated by the water collection tank 4. The lower end of the inlet pipe is fixedly connected to the nozzle, which can accelerate and pressurize the collected water flow to form a high-speed concentrated jet. The runner is rotatably installed inside the housing, and the nozzle is positioned directly above the runner, so that the high-speed water flow ejected from the nozzle can accurately and vertically impact the runner, driving the runner to rotate continuously. This efficiently converts the gravitational potential energy and kinetic energy of the water flow into the mechanical energy of the runner's rotation, providing a stable power input for the subsequent operation of the fan. This device has a simple structure and smooth water intake, which can effectively avoid the problem of low power conversion efficiency caused by insufficient water pressure.

[0029] Furthermore, this disclosure is not limited to the aforementioned impulse turbine structure. In conditions where the cooling tower head is high and flow fluctuations are small, a mixed-flow turbine can be used to improve conversion efficiency. Alternatively, a flow-generator system combined with a motor-generator set can be used, suspending multiple "narrow-slot flow generators" above the water collection pool. Each slot contains a small rotor; the water flow rotates the rotor, driving the micro-generator to generate electricity. The generated energy is then collected, inverted, and centrally used to drive the traditional fan at the top of the tower or surrounding distributed fans, achieving power output. A hydraulic pump-motor system can also be used, utilizing water flow to drive a hydraulic pump, generating high-pressure hydraulic oil, which is then used by a hydraulic motor to drive the fan. This system easily achieves stepless speed regulation and flexible transmission, suitable for situations where fans are distributed and require a wide range of speed adjustments. All of these alternative solutions can achieve the invention's objective of recovering the potential energy of circulating water and driving fan operation.

[0030] Furthermore, the turbine 5 can be a double-impact turbine with a hollow, through-type runner. The open space of the hollow, through-type runner creates a secondary impact channel. High-speed water jets ejected from the nozzles first impact the upper blades of the runner, completing the first energy exchange. The water then passes through the runner's interior via the hollow, through-type structure, impacting the lower blades again, achieving a second power output. By fully utilizing the kinetic energy of the water flow through two consecutive impacts, the water energy conversion efficiency under low head and normal pressure conditions is significantly improved, avoiding the problems of low water energy utilization and energy waste associated with single impacts. Simultaneously, the hollow, through-type runner structure effectively guides the water flow, preventing stagnation and accumulation inside the runner, reducing runner rotational resistance, minimizing cavitation and water flow impact losses, and ensuring the turbine's continuous, efficient, and stable output of mechanical energy.

[0031] In some embodiments, multiple blades are evenly arranged on the outer circumference of the impeller, with a straight upper section and a curved lower section. The straight upper section of the blade directly faces the high-speed water jet from the nozzle, maximizing the area to receive the high-speed jet, resulting in uniform force and direct impact, effectively reducing water flow impact loss and improving the energy absorption efficiency of the water flow impact work. The curved lower section of the blade precisely guides and constrains the impacted water flow, conforming to the water flow trajectory and smoothly discharging the water, reducing waste energy consumption. This segmented, irregularly shaped blade structure matches the high flow rate and low drop characteristics of the cooling tower, effectively optimizing the blade inlet impact posture and outlet flow pattern, improving the overall stress state of the impeller, reducing hydraulic losses, significantly improving the overall water energy conversion efficiency of the impeller, and reducing lateral scouring and wear on the blades, thus improving the stability and service life of the entire unit. Specifically, the number of blades can be 24 to 36, adjusted according to the design flow rate and rotational speed. The impeller material can be duplex stainless steel, which is resistant to cavitation and erosion.

[0032] Furthermore, a tungsten carbide coating can be applied to the outer surface of the blades. Blades are constantly subjected to complex operating conditions involving high-speed water flow, water vapor erosion, and slight cavitation, making them highly susceptible to surface wear and corrosion defects, which can affect the rotor's rotational balance and the accuracy of water energy conversion. By adding a tungsten carbide coating to the outer surface of the blades, the excellent properties of tungsten carbide—high hardness, strong wear resistance, erosion resistance, and corrosion resistance—can be utilized to form a dense, high-strength protective layer on the blade surface. This effectively resists surface damage caused by impurities in the circulating water, water vapor corrosion, and hydraulic cavitation, significantly reducing the blade wear rate.

[0033] Reference Figure 1The transmission mechanism 7 may include a speed increaser 71, an overrunning clutch, and an electromagnetic clutch 72 connected in sequence. The input shaft of the speed increaser 71 is connected to the shaft of the turbine 5, and can receive the low-speed, high-torque power output from the turbine 5. The output end of the electromagnetic clutch 72 is connected to the fan 6, and is used to output driving power to the fan 6 at a matching speed. Due to the variation in the cooling tower's circulating water drop and flow rate with operating conditions, the turbine's output speed is generally low and fluctuates, which cannot directly meet the fan's rated operating speed requirements. By adding the speed increaser 71, the low output speed of the turbine 5 can be increased, achieving speed and power matching, and ensuring that the fan 6 operates in its high-efficiency range. The overrunning clutch enables unidirectional power transmission. In cases where the turbine 5's output power is insufficient, its speed is too low, or it is shut down, it automatically cuts off the reverse resistance on the turbine 5 side, preventing the fan 6 from dragging the turbine 5 backwards and preventing equipment from reversing or jamming. The electromagnetic clutch 72 enables controllable engagement and disengagement of power, allowing for flexible control of the start-up and shutdown of a single wind turbine 6 and power supply according to system operating requirements. It also provides overload protection, effectively preventing damage to transmission components caused by abnormal loads. This structure, through multi-stage coordination of speed-increasing, one-way, and controllable clutches, achieves smooth and safe power transmission between the turbine 5 and the wind turbine 6, improving the reliability of the device.

[0034] It should be noted that this disclosure is not limited to the structure of the above-mentioned speed transmission mechanism 7. The speed increaser can be eliminated and a direct drive structure can be adopted. Under the premise that the speed of the water turbine and the wind turbine can be matched, the transmission efficiency can be further improved. Alternatively, a hydraulic coupler can be added between the speed increaser and the wind turbine to achieve flexible start and stop, smooth speed regulation and deviation compensation, reduce the equipment alignment and assembly accuracy requirements, and improve the shock resistance of the transmission system.

[0035] Among them, the speed increaser 71 can be a planetary gear speed increaser. Planetary gear speed increasers feature a wide transmission ratio range, high speed increase accuracy, compact structure, and strong load-bearing capacity, making them suitable for the low-speed, high-torque output characteristics of the water turbine 5. Compared to ordinary cylindrical gear speed increase structures, planetary gear speed increasers, through the synchronous meshing of multiple sets of planetary gears, achieve a more uniform load distribution, stably increasing the low speed of the water turbine 5 to the rated operating speed required by the wind turbine 6, with high speed matching accuracy and low power transmission loss. Specifically, the speed increaser 71 internally adopts a single-stage or two-stage planetary gear structure to increase the low speed of the water turbine 5 (e.g., 50rpm~150rpm) to the high speed required by the wind turbine (e.g., 300rpm~750rpm).

[0036] As an exemplary embodiment of this disclosure, the circulating water potential energy recovery device may further include a water flow sensor installed at the inlet of the turbine 5, a wind speed sensor installed at the outlet of the fan 6, and a water temperature sensor installed inside the collection tank 3. The water flow sensor can detect hydraulic parameters such as the flow rate and velocity of the water entering the turbine 5 in real time, accurately reflecting the real-time water flow conditions of the cooling tower's circulating water, and providing data support for judging the power output status of the turbine 5. The wind speed sensor can monitor the outlet wind speed and air volume parameters of the fan 6 in real time, intuitively reflecting the actual ventilation operating status of the fan 6, facilitating the judgment of the cooling tower's ventilation and heat exchange efficiency. The water temperature sensor is used to collect circulating water temperature data in real time, accurately reflecting the cooling tower's heat exchange load and water temperature changes. Through multi-point sensor collaborative monitoring, the device's hydraulic operating parameters, ventilation parameters, and water temperature operating parameters can be comprehensively collected, achieving real-time perception of the equipment's operating status and accurate capture of operating condition changes. This provides reliable data for the potential energy recovery device's operating condition adaptation and adjustment, fault warning, and efficient operation, effectively improving the device's intelligent monitoring level and operating condition adaptation capability.

[0037] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0038] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0039] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A circulating water potential energy recovery device, characterized in that, include: The cooling tower body has water-spraying packing material arranged on the upper part of the cooling tower body, and a water collection pool is provided at the bottom of the cooling tower body; A water collection tank is installed inside the cooling tower body and located between the water spray packing and the water collection pool; A water turbine, wherein the water inlet of the water turbine is connected to the water outlet of the water collection tank; Multiple fans are evenly arranged along the circumference of the inner or outer wall of the cooling tower. A variable speed transmission mechanism is connected between the water turbine and the wind turbine; and The control mechanism is electrically connected to the water turbine and the wind turbine, respectively.

2. The circulating water potential energy recovery device according to claim 1, characterized in that, The water collection tank is conical in shape, and the tank wall is arranged downward from the side wall of the cooling tower to the central axis.

3. The circulating water potential energy recovery device according to claim 2, characterized in that, The inner wall of the water collection tank is equipped with guide fins.

4. The circulating water potential energy recovery device according to claim 1, characterized in that, The water turbine is an impulse water turbine, which includes an inlet pipe, a nozzle, a runner, and a housing. The upper end of the inlet pipe is connected to the outlet of the water collection tank, and the lower end of the inlet pipe is fixedly connected to the nozzle. The runner is rotatably installed inside the housing, and the nozzle is located directly above the runner.

5. The circulating water potential energy recovery device according to claim 4, characterized in that, The turbine is a double-impact turbine, and the runner has a hollow through-type structure.

6. The circulating water potential energy recovery device according to claim 4, characterized in that, The outer circumference of the rotor is uniformly provided with multiple blades, the upper part of which is a straight section and the lower part is a curved section.

7. The circulating water potential energy recovery device according to claim 6, characterized in that, The outer surface of the blade is coated with tungsten carbide.

8. The circulating water potential energy recovery device according to claim 1, characterized in that, The speed change transmission mechanism includes a speed increaser, an overrunning clutch, and an electromagnetic clutch connected in sequence. The input shaft of the speed increaser is connected to the rotating shaft of the water turbine, and the output end of the electromagnetic clutch is connected to the wind turbine.

9. The circulating water potential energy recovery device according to claim 8, characterized in that, The speed increaser is a planetary gear speed increaser.

10. The circulating water potential energy recovery device according to claim 9, characterized in that, The circulating water potential energy recovery device also includes a water flow sensor installed at the turbine inlet, a wind speed sensor installed at the fan outlet, and a water temperature sensor installed inside the water collection tank.

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