A new type of internal and external integrated circulation cooling tower

Abstract

The invention discloses a novel inner-outer integrated circulating cooling tower, comprising an inner tower and an outer tower; a cold hole is provided between the inner tower and the outer tower, and the cold hole passes through the outer tower and is connected to the inner tower; a pressure pipe, a circulating water spray device and a water reservoir are provided in the inner tower, the water reservoir is provided at the bottom of the inner tower, an exhaust pipe is provided at the top of the inner tower, and a negative pressure fan is provided in the exhaust pipe; a cold source storage chamber is provided between the outer tower and the inner tower; the pressure pipe is connected with the circulating water spray device, and the inner tower is connected with the cold hole through the exhaust pipe at the top of the tower, and the cold hole passes through the cold source storage chamber; the pressure pipe transports high-temperature circulating water to the circulating water spray device to form a water sprinkling area through atomization, and the external air enters the inner tower after being cooled through the cold hole, and cools the high-temperature circulating water in the water sprinkling area, and the cooled circulating water enters the water reservoir, and the wet hot water vapor generated in the cooling process enters the exhaust pipe, and is cooled, and is introduced into the cold hole by the negative pressure fan in the exhaust pipe and enters the inner tower.

Description

Technical Field

[0001] The present invention relates to a cooling tower for a power plant, wherein waste water vapor is cooled and then recirculated into the tower and the temperature of the air entering the tower is reduced, so that the circulating water is kept at an optimal temperature for stable operation. More specifically, the invention relates to a novel inner and outer integrated circulating cooling tower. Background Art

[0002] Cooling towers are important heat and mass transfer equipment in the power generation process of power plants. The function of cooling towers is to dissipate the heat of high-temperature cooling water into the atmosphere and reduce the temperature of circulating cooling water through heat and mass exchange. The cooling water mainly relies on the mixing and contact of hot and cold fluids in the cooling tower. With the help of the water vapor partial pressure difference between the two fluids, the hot fluid is partially evaporated and cooled itself. Whether the cooling tower can work properly is a necessary condition for full-load generators and safe power generation. Only when the cooling tower has sufficient cooling effect and provides enough cooling water to the condenser of the steam turbine generator set can the vacuum degree of the condenser be guaranteed. The lower the temperature of the cooling water, the greater the work done by the same amount of steam, and the higher its effective utilization rate. Therefore, whether the cooling tower can achieve the desired effect is an important condition for whether power generation can save coal, electricity, water, and energy and reduce the cost of power generation.

[0003] The function of the existing cooling tower is to organize airflow, form natural suction, draw cold air into the tower, and discharge the warm steam in the tower into the air in an organized manner, reducing the vortex of hot and humid steam and reducing ventilation resistance. The circulating water completes heat exchange in the cooling tower by heat transfer and evaporation. However, the cooling effect of the cooling tower is affected by factors such as natural temperature conditions. The circulating water temperature is uncontrollable, and the actual temperature of the circulating water is quite different from the designed optimal temperature. The heat exchange effect of the circulating cooling water is low, and the hot and humid steam is discharged outside the tower, resulting in waste of resources and high power generation costs. In addition, after the cold northern regions enter winter, the ambient temperature can drop to -35°C, with a temperature difference of 15°C between day and night. The cold air is too low and the daily temperature difference is uncertain, causing the air in the tower to be too cold, causing the cooling tower water distribution system, water sprinkling system and filling device to be damaged by ice.

[0004] At present, in order to prevent the circulating cooling tower from severe icing and damaging the equipment, the cooling tower air inlet of most units is enclosed by hanging wind shields; and Europe has recently adopted a multi-layer metal mesh ice curtain anti-freezing method to block cold air, so as to reduce the amount of air entering the cooling tower, thereby controlling the circulating cooling tower and its ancillary equipment from icing.

[0005] However, the law of temperature change in winter is high during the day and low at night, which causes the vacuum of the unit to show a trend of low during the day and high at night, which is contrary to the method of unit load change trend of high during the day and low at night. In order to ensure the antifreeze safety of the circulating cooling tower, the number of suspended wind shields should meet the safe operation needs of the load trough, the lowest ambient temperature in the second half of the night, and the unit vacuum high period. However, as the ambient temperature rises, the unit load gradually increases, which is not conducive to the economic operation of the unit. Since the above method is greatly affected by the ambient temperature and time period, it cannot meet the requirements of adjustment at any time according to the ambient temperature and load changes.

[0006] Therefore, how to provide a new type of integrated internal and external circulation cooling tower is a problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a novel internal and external integrated circulating cooling tower to solve the problems mentioned in the background technology.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A novel internal and external integrated circulating cooling tower includes an outer tower and a cold tunnel. The outer tower includes an inner tower and a cold source storage chamber. The cold tunnel passes through the cold source storage chamber and is connected to the inner tower. External air is introduced into the inner tower through the air inlet of the cold tunnel.

[0010] The inner tower is equipped with a pressure pipe, a circulating water spray device and a water reservoir. The pressure pipe is connected to the circulating water spray device. The water reservoir is located at the bottom of the inner tower. The top of the inner tower is equipped with an exhaust pipe, which is connected to the cold tunnel. A negative pressure fan is installed in the exhaust pipe.

[0011] The pressure pipe transports the high-temperature circulating water to the circulating water spray device, which atomizes the high-temperature circulating water to form a water sprinkling area. The external air is cooled through the cold hole and then enters the inner tower to exchange heat with the atomized water droplets, generating cooling circulating water and wet hot water vapor. The cooling circulating water falls into the water reservoir, and the wet hot water vapor rises to the exhaust pipe and is introduced into the cold hole and into the inner tower by the negative pressure fan in the exhaust pipe.

[0012] Preferably, a liquid nitrogen injection port is provided on the exhaust pipe for injecting liquid nitrogen to cool the wet hot water vapor in the exhaust pipe.

[0013] Preferably, the exhaust pipe includes an exhaust main pipe and an exhaust branch pipe, the inner tower is connected to the exhaust main pipe through the exhaust branch pipe, the exhaust main pipe is connected to the cold tunnel, and the negative pressure fan is arranged in the exhaust main pipe.

[0014] Preferably, a steam-water separator is provided at the outlet of each exhaust main pipe, and the negative pressure fan leads the cooled water vapor to the steam-water separator, and after separation, the water vapor enters the inner tower through the cold tunnel.

[0015] Preferably, a seasonal spray cooling device is provided at the air inlet of the cold cave, the seasonal spray cooling device comprises a nozzle and a cold source pipe, and the seasonal spray cooling device is connected to the cold source storage chamber through the cold source pipe;

[0016] The seasonal spray cooling device obtains cold source through the cold source pipe, sprays the cold source through the nozzle and transports it to the water spraying area together with the external air, and cools the water droplets atomized by the circulating water spray device in the water spraying area;

[0017] The seasonal spray cooling device switches the cold source pipe according to the changes in the external ambient temperature.

[0018] Preferably, the cold source pipeline of the seasonal spray cooling device includes a spring pipeline, a summer pipeline, an autumn pipeline and an external primary water source pipeline;

[0019] The spring pipeline and the summer pipeline are respectively connected to the external primary water source pipeline, the summer pipeline passes through the cold source storage room, and the autumn pipeline is connected to the cold source storage room;

[0020] The cold source of the pipeline in spring is the external primary natural water source, the cold source of the pipeline in summer is the primary natural water source after secondary cooling in the cold source storage room, and the cold source of the pipeline in autumn is the water source directly extracted from the cold source storage room.

[0021] Preferably, the cold source of the cold source storage chamber is ultra-low temperature liquid water or solid ice.

[0022] Preferably, the novel internal and external integrated circulating cooling tower further comprises a spray icing automatic air regulating device, which comprises a metal mesh, a winter spray device, a water pump and an intelligent temperature controller; the metal mesh is arranged in the cold tunnel, the winter spray device is arranged at the air inlet of the cold tunnel, the water pump is arranged in the water reservoir, and the intelligent temperature controller is connected to the water pump;

[0023] The intelligent temperature controller controls the start and stop of the water pump according to the temperature of the circulating water in the water reservoir; when the temperature of the circulating water in the water reservoir reaches the set lower limit threshold, the water pump is controlled to start and the circulating water is transported to the winter spray device. The water droplets sprayed by the winter spray device fall on the metal mesh and form an ice film under the action of cold air, which makes the aperture of the metal mesh smaller and the air intake in the cold cave reduced; when the temperature of the circulating water in the water reservoir rises to the set upper limit threshold, the intelligent temperature controller controls the water pump to stop, the ice film sublimates, the aperture of the metal mesh expands, and the air intake increases.

[0024] Preferably, a negative pressure draft box is also provided in the inner tower, which is located at the center of the inner tower and is used to introduce the air in the cold cave into the center of the inner tower.

[0025] Preferably, the water reservoir is provided with a circulating water outlet culvert, and a hydroelectric generator is provided at the circulating water outlet culvert, which supplies power to the equipment in the tower.

[0026] Through the above technical solutions, it can be seen that compared with the prior art, the present invention discloses a novel integrated internal and external circulating cooling tower, which recycles wet hot water vapor and reduces resource waste; fully utilizes the low-temperature water source and the cold source of the storage room through the seasonal spray cooling device to reduce the temperature of the air entering the tower, overcomes the adverse effects of conditions such as natural environmental temperature changes, and enables the circulating water to operate within the optimal temperature range in different seasons; automatically controls the air inlet of the tower through the spray freezing automatic air regulating device, which can effectively resolve the contradiction between the circulating water temperature and the freezing damage of the cooling tower in the cold winter, so that the circulating water can operate stably within the optimal temperature; maintains the salt balance of the circulating water source; optimizes the economic operation of the cold end circulating water, reduces the water supply to the cooling tower, optimizes the number of water pumps, and reduces operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0028] Figure 1 The accompanying drawing is a schematic structural diagram of a novel internal and external integrated circulating cooling tower provided by the present invention;

[0029] Among them, 1-inner tower, 2-outer tower, 3-pressure pipe, 4-negative pressure draft box, 5-circulating water spray device, 6-circulating water outlet culvert, 7-liquid nitrogen injection port, 8-exhaust branch pipe, 9-exhaust main pipe, 10-negative pressure fan, 11-steam-water separator, 12-water pump, 13-cold tunnel, 14-air inlet, 15-spring pipeline, 16-summer pipeline, 17-autumn pipeline, 18-spray freezing air regulation device, 19-metal mesh, 20-cold source storage room, 21-hydroelectric generator. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] The embodiment of the present invention discloses a novel inner and outer integrated circulation cooling tower. Figure 1, including: an outer tower 2 and a cold cave 13, the outer tower 2 includes an inner tower 1 and a cold source storage chamber 20, the cold cave 13 passes through the cold source storage chamber 20 and is connected to the inner tower 1, and the external air is introduced into the inner tower 1 through the air inlet 14 of the cold cave 13;

[0032] A pressure pipe 3, a circulating water spray device 5 and a water reservoir are provided in the inner tower 1. The pressure pipe 3 is connected to the circulating water spray device 5. The water reservoir is provided at the bottom of the inner tower 1. An exhaust pipe is provided at the top of the inner tower 1. The exhaust pipe is connected to the cold tunnel 13. A negative pressure fan 10 is provided in the exhaust pipe.

[0033] The pressure pipe 3 transports the high-temperature circulating water to the circulating water spray device 5, which atomizes the high-temperature circulating water to form a water sprinkling area. The external air is cooled through the cold hole 13 and then enters the inner tower 1 to exchange heat with the atomized water droplets, generating cooling circulating water and wet hot water vapor. The cooling circulating water falls into the water reservoir, and the wet hot water vapor rises to the exhaust pipe and is introduced into the cold hole 13 by the negative pressure fan 10 in the exhaust pipe and enters the inner tower 1.

[0034] In practical applications, the outer tower 2 is a closed tower built outside the inner tower 1 and connected to the inner tower 1. The space between the inner tower 1 and the outer tower 2 is a cold source storage chamber 20.

[0035] Under the action of the negative pressure fan 10, the air flow is organized to form a stable suction force, and the external air is introduced into the inner tower 1 through the cold hole 13.

[0036] In this embodiment, the principle of the circulating water spray device 5 is: using the pressure of the closed vertical shaft itself, inputting it into the nozzle through the pressure pipe 3, the sprayed atomized water droplets have a particle size of 300-800 microns, and the water droplets fully contact with the cold air during the falling process, completing heat exchange by evaporation, conduction, etc.

[0037] In order to further implement the above technical solution, a liquid nitrogen injection port 7 is provided on the exhaust pipe for injecting liquid nitrogen to cool the wet hot water vapor in the exhaust pipe.

[0038] In order to further implement the above technical solution, the exhaust pipe includes an exhaust main pipe 9 and an exhaust branch pipe 8. The inner tower 1 is connected to the exhaust main pipe 9 through the exhaust branch pipe 8. The exhaust main pipe 9 is connected to the cold tunnel 13. The negative pressure fan 10 is arranged in the exhaust main pipe 9.

[0039] The exhaust pipes include N groups, each group of exhaust pipes includes a main exhaust pipe and a plurality of branch exhaust pipes, and each branch exhaust pipe in each group is connected to the main exhaust pipe.

[0040] In order to further implement the above technical solution, a steam-water separator 11 is provided at the outlet of each exhaust main pipe 9 , and the negative pressure fan 10 leads the cooled water vapor to the steam-water separator 11 , and after separation, the water vapor enters the inner tower 1 through the cold tunnel 13 .

[0041] In order to further implement the above technical solution, a seasonal spray cooling device is provided at the air inlet 14 of the cold tunnel 13. The seasonal spray cooling device includes a nozzle and a cold source pipe. The seasonal spray cooling device is connected to the cold source storage chamber through the cold source pipe.

[0042] The seasonal spray cooling device obtains cold source through the cold source pipe, sprays the cold source through the nozzle and transports it to the watering area together with the external air to cool the watering area;

[0043] The seasonal spray cooling device switches the cold source pipe according to the changes in the external ambient temperature.

[0044] In order to further implement the above technical solution, the cold source pipeline of the seasonal spray cooling device includes a spring pipeline 15, a summer pipeline 16, an autumn pipeline 17 and an external primary water source pipeline;

[0045] The spring pipe 15 and the summer pipe 16 are respectively connected to the external primary water source pipe. The summer pipe 16 passes through the cold source storage chamber, and the autumn pipe 17 is connected to the cold source storage chamber 20.

[0046] The cold source of the pipeline in spring is the external primary natural water source, the cold source of the pipeline in summer is the primary natural water source after secondary cooling in the cold source storage room, and the cold source of the pipeline in autumn is the water source directly extracted from the cold source storage room.

[0047] In order to further implement the above technical solution, the cold source of the cold source storage chamber 20 is ultra-low temperature liquid water or solid ice.

[0048] In this embodiment, the working principle of the seasonal spray cooling device is as follows: a spray pipe is installed in the air inlet cold tunnel, a spray nozzle is installed in the spray pipe, and low-temperature water from the cold source is used as the air coolant. The low-temperature water from the cold source is sprayed out by the spray nozzle and atomized into tiny particles of water droplets with a fast flow rate. The water diffuses in the cold tunnel to disturb the air and generate a wind source, forming an air cooling zone in the cold tunnel, and enters the shower zone with a double flow of air and mist to evaporate and absorb heat, providing a cold source for cooling the circulating water.

[0049] In actual application, seasonal spray cooling device replaces and uses different pipes alternately or combines them for common use according to the set temperature.

[0050] The role of cold source storage: After winter, the air temperature rises. In order to maintain a lower inlet air temperature, a cold source is provided for the heat exchange of the circulating water in the cooling tower, the inlet air temperature is reduced, and the circulating water temperature of the conventional cooling tower is changed from uncontrollable due to the influence of the natural ambient temperature to controllable. The purpose is to reduce the circulating water temperature, improve the efficiency of the cooling tower, and keep the circulating water temperature within the optimal range.

[0051] Cold source storage method: After the winter solstice, a natural water source is introduced into the cold source storage room in batches. Ultra-low temperature liquid water is stored in the southern region, and solid ice is stored in the northern region.

[0052] In order to further implement the above technical solution, a novel integrated internal and external circulating cooling tower further includes a spray icing automatic air regulating device 18, which includes a metal mesh 19, a winter spray device, a water pump 12 and an intelligent temperature controller; the metal mesh 19 is arranged in the cold tunnel 13, the winter spray device is arranged at the air inlet 14 of the cold tunnel 13, the water pump 12 is arranged in the water reservoir, and the intelligent temperature controller is connected to the water pump;

[0053] The intelligent temperature controller controls the start and stop of the water pump according to the temperature of the circulating water in the water reservoir; when the temperature of the circulating water in the water reservoir reaches the set lower limit threshold, the water pump is controlled to start and the circulating water is transported to the winter spray device. The water droplets sprayed by the winter spray device fall on the metal mesh and form an ice film under the action of cold air, which makes the aperture of the metal mesh smaller and the air intake in the cold cave reduced; when the temperature of the circulating water in the water reservoir rises to the set upper limit threshold, the intelligent temperature controller controls the water pump to stop, the ice film sublimates, the aperture of the metal mesh expands, and the air intake increases.

[0054] In this embodiment, the intelligent temperature controller includes a temperature sensor, a time relay, an ice film thickness regulator and an AC contactor connected to the water pump motor; the circulating water temperature is detected by the temperature sensor, and the temperature threshold value of the lower limit start and the upper limit stop is set. When the circulating water temperature reaches the lower limit, the intelligent temperature controller is connected to the power supply and the water pump is started. When the temperature reaches the upper limit, the water pump automatically stops. The intelligent temperature controller is controlled by a PLC programmable controller.

[0055] In order to further implement the above technical solution, a negative pressure draft box 4 is also provided in the inner tower. The negative pressure draft box 4 is located at the center of the inner tower 1 and is used to introduce the air in the cold cave 13 into the center of the inner tower 1.

[0056] In order to further implement the above technical solution, the water reservoir is provided with a circulating water outlet culvert 6, and a hydroelectric generator 21 is provided at the circulating water outlet culvert 6 to supply power to the equipment in the tower.

[0057] In this embodiment, a new type of integrated internal and external circulation cooling tower is provided with an automatic control system in the middle tower to automatically control the seasonal spray cooling device, the spray icing automatic air adjustment device, the negative pressure fan, the negative pressure draft box, etc., and is programmably controlled by PLC.

[0058] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0059] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A new type of internal and external integrated circulating cooling tower, characterized in that: include: The outer tower and the cold tunnel include the inner tower and the cold source storage room. The cold tunnel passes through the cold source storage room and is connected to the inner tower. External air is introduced into the inner tower through the air inlet of the cold tunnel. The inner tower is equipped with a pressure pipe, a circulating water spray device and a water reservoir. The pressure pipe is connected to the circulating water spray device. The water reservoir is located at the bottom of the inner tower. The top of the inner tower is equipped with an exhaust pipe, which is connected to the cold tunnel. A negative pressure fan is installed in the exhaust pipe. The pressure pipe transports the high-temperature circulating water to the circulating water spray device, which atomizes the high-temperature circulating water to form a water sprinkling area. The external air is cooled through the cold hole and then enters the inner tower to exchange heat with the atomized water droplets, generating cooling circulating water and wet hot water vapor. The cooling circulating water falls into the water reservoir, and the wet hot water vapor rises to the exhaust pipe and is introduced into the cold hole and into the inner tower by the negative pressure fan in the exhaust pipe.

2. A novel internal and external integrated circulation cooling tower according to claim 1, characterized in that: A liquid nitrogen injection port is provided on the exhaust pipe for injecting liquid nitrogen to cool the wet hot water steam in the exhaust pipe.

3. A novel internal and external integrated circulation cooling tower according to claim 1, characterized in that: The exhaust pipe includes an exhaust main pipe and an exhaust branch pipe. The inner tower is connected to the exhaust main pipe through the exhaust branch pipe. The exhaust main pipe is connected to the cold tunnel. The negative pressure fan is installed in the exhaust main pipe.

4. A novel internal and external integrated circulation cooling tower according to claim 3, characterized in that: A steam-water separator is installed at the outlet of each exhaust main pipe. The negative pressure fan leads the cooled water vapor to the steam-water separator, and after separation, it enters the inner tower through the cold tunnel.

5. The novel internal and external integrated circulation cooling tower according to claim 1 is characterized in that: A seasonal spray cooling device is provided at the air inlet of the cold tunnel. The seasonal spray cooling device comprises a nozzle and a cold source pipe. The seasonal spray cooling device is connected to the cold source storage chamber through the cold source pipe. The seasonal spray cooling device obtains cold source through the cold source pipe, sprays the cold source through the nozzle and transports it to the water spraying area together with the external air, and cools the water droplets atomized by the circulating water spray device in the water spraying area; The seasonal spray cooling device switches the cold source pipe according to the changes in the external ambient temperature.

6. A novel internal and external integrated circulation cooling tower according to claim 5, characterized in that: The cold source pipelines of the seasonal spray cooling device include spring pipelines, summer pipelines, autumn pipelines and external primary water source pipelines; The spring pipeline and the summer pipeline are respectively connected to the external primary water source pipeline, the summer pipeline passes through the cold source storage room, and the autumn pipeline is connected to the cold source storage room; The cold source of the pipeline in spring is the external primary natural water source, the cold source of the pipeline in summer is the primary natural water source after secondary cooling in the cold source storage room, and the cold source of the pipeline in autumn is the water source directly extracted from the cold source storage room.

7. The novel internal and external integrated circulation cooling tower according to claim 1 is characterized in that: The cold source of the cold source storage room is ultra-low temperature liquid water or solid ice.

8. The novel internal and external integrated circulation cooling tower according to claim 1 is characterized in that: It also includes a spray icing automatic air regulating device, which includes a metal mesh, a winter spray device, a water pump and an intelligent temperature controller; the metal mesh is arranged in the cold cave, the winter spray device is arranged at the air inlet of the cold cave, the water pump is arranged in the water reservoir, and the intelligent temperature controller is connected to the water pump; The intelligent temperature controller controls the start and stop of the water pump according to the temperature of the circulating water in the water reservoir; when the temperature of the circulating water in the water reservoir reaches the set lower limit threshold, the water pump is controlled to start and the circulating water is transported to the winter spray device. The water droplets sprayed by the winter spray device fall on the metal mesh and form an ice film under the action of cold air, which makes the aperture of the metal mesh smaller and the air intake in the cold cave reduced; when the temperature of the circulating water in the water reservoir rises to the set upper limit threshold, the intelligent temperature controller controls the water pump to stop, the ice film sublimates, the aperture of the metal mesh expands, and the air intake increases.

9. The novel internal and external integrated circulation cooling tower according to claim 1 is characterized in that: There is also a negative pressure draft box in the inner tower, which is located in the center of the inner tower and is used to introduce the air in the cold cave into the center of the inner tower.

10. The novel internal and external integrated circulation cooling tower according to claim 1 is characterized in that: The water reservoir is equipped with a circulating water outlet culvert, where a hydroelectric generator is installed to supply power to the equipment inside the tower.

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