CN-121994064-A - Automatic water distribution device and method for water collection tank at bottom of radiator of SCAL type indirect cooling system

CN121994064ACN 121994064 ACN121994064 ACN 121994064ACN-121994064-A

Abstract

The invention belongs to the technical field of chemical corrosion prevention, and relates to an automatic water distribution device and method for a water collection tank at the bottom of a radiator of a SCAL type indirect cooling system. The device comprises a detection control system and a mechanical unit system, wherein the detection control system comprises a control device, an electromagnetic regulating valve and a flowmeter, the mechanical unit system comprises a carbon steel water inlet pipe, an intermediate cold water distributor, an aluminum pipe-to-carbon steel pipe joint and an aluminum feeding pipe, the water outlet end of the carbon steel water inlet pipe is sequentially connected with the flowmeter and the electromagnetic regulating valve and then is communicated with the water inlet of the intermediate cold water distributor, a plurality of water outlets of the intermediate cold water distributor are correspondingly connected with a plurality of aluminum feeding pipes through the aluminum pipe-to-carbon steel pipe joint, the signal output end of the flowmeter is connected with the control device, and the control output end of the control device is connected with the electromagnetic regulating valve. The invention ensures the consistency of the flow rate and the flow velocity of the water flow finally entering each water feeding aluminum pipe, thereby effectively solving the problems of uneven hydraulic distribution and local high-speed flushing caused by the water feeding mode of the traditional water collecting tank.

Inventors

CHANG HAO
ZHANG HONGBO
XIAO HAIGANG
GUO YAN
HUANG SHANFENG
Hao Hongduo
LIU TAO

Assignees

西安热工研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20260310

Claims (10)

1. The automatic water distribution device for the water collection tank at the bottom of the radiator of the SCAL indirect cooling system is characterized by comprising a detection control system and a mechanical unit system, wherein the detection control system comprises a control device (7), an electromagnetic regulating valve (14) and a flowmeter (15), and the mechanical unit system comprises a carbon steel water inlet pipe (16), an indirect cooling water distributor (3), an aluminum pipe-carbon conversion steel pipe joint (2) and an aluminum water inlet pipe (1); the water outlet end of the carbon steel water inlet pipe (16) is sequentially connected with the flowmeter (15) and the electromagnetic regulating valve (14) and then communicated with the water inlet of the indirect water-cooling water distributor (3), and a plurality of water outlets of the indirect water-cooling water distributor (3) are correspondingly connected with a plurality of water-feeding aluminum pipes (1) through the aluminum pipe carbon-conversion steel pipe joint (2); The signal output end of the flowmeter (15) is connected with the signal input end of the control device (7), and the control output end of the control device (7) is connected with the control end of the electromagnetic regulating valve (14).
2. The automatic water distribution device for the water collection tank at the bottom of the heat radiator of the SCAL type indirect cooling system according to claim 1, wherein the flowmeter (15) is a time difference type ultrasonic flowmeter.
3. The automatic water distribution device for the water collection tank at the bottom of the radiator of the SCAL type indirect cooling system according to claim 1 is characterized in that the upstream and the downstream of the flowmeter (15) are respectively provided with a straight pipe section meeting the measurement precision requirement of the flowmeter (15).
4. The automatic water distribution device for the water collection tank at the bottom of the SCAL indirect cooling system radiator is characterized in that the aluminum pipe-to-carbon steel pipe joint (2) comprises an aluminum pipe and a carbon steel pipe connected with the aluminum pipe, the aluminum pipe is connected with the water supply aluminum pipe (1), the carbon steel pipe is connected with the indirect cooling water distributor (3), and an annular rubber ring is arranged between the aluminum pipe and the carbon steel pipe.
5. The automatic water distribution device for the water collection tank at the bottom of the SCAL inter-cooling system radiator according to claim 1, wherein the number of water outlets of the inter-cooling water distributor (3) is ten, and the ten water outlets are arranged in two parallel rows.
6. The automatic water distribution device for the water collection tank at the bottom of the SCAL type indirect cooling system radiator according to claim 1, wherein eight indirect cooling water distributors (3) are arranged on each SCAL type indirect cooling system radiator.
7. The automatic water distribution device for the water collection tank at the bottom of the SCAL type inter-cooling system radiator according to claim 1 is characterized in that signal output ends of a plurality of flow meters (15) connected with the same SCAL type inter-cooling system radiator are commonly connected to the same control device (7), and control output ends of the control device (7) are connected with control ends of a plurality of electromagnetic regulating valves (14) corresponding to the SCAL type inter-cooling system radiator in a one-to-one correspondence mode.
8. The automatic water distribution device for the water collection tank at the bottom of the SCAL type indirect cooling system radiator according to claim 1 is characterized in that the mechanical unit system further comprises an indirect cooling water distributor support (12) and an upward water aluminum pipe support (13), the indirect cooling water distributor (3) is fixed through the indirect cooling water distributor support (12), and the upward water aluminum pipe (1) is fixed through the upward water aluminum pipe support (13).
9. An automatic water distribution method for a water collection tank at the bottom of a radiator of an SCAL indirect cooling system is characterized by comprising the following steps based on the device of any one of claims 1-8: starting a circulating water pump, and enabling hot water from a condenser to enter a water inlet of the indirect cold water distributor (3) after passing through the flowmeter (15) and the electromagnetic regulating valve (14) in sequence through the carbon steel water inlet pipe (16); The flowmeter (15) detects the flow of hot water in the pipeline in real time and transmits a flow signal to the control device (7); the control device (7) generates a regulating instruction according to a received flow signal and a preset control logic, and sends the regulating instruction to the electromagnetic regulating valve (14), wherein the electromagnetic regulating valve (14) changes the opening degree according to the received regulating instruction so as to regulate the flow of hot water flowing through a pipeline where the electromagnetic regulating valve (14) is positioned; the hot water after flow adjustment is evenly distributed to each water outlet through the indirect water distributor (3), enters the corresponding water feeding aluminum pipe (1) through each aluminum pipe carbon-conversion steel pipe joint (2), and is finally conveyed to a water collecting tank at the bottom of the radiator to complete the automatic water distribution process.
10. The automatic water distribution method for the water collection tank at the bottom of the heat radiator of the SCAL type indirect cooling system according to claim 9, wherein the preset control logic comprises: After the circulating water pump is started, the control device (7) waits for a first preset time period, and then reads flow data X 1 ,X 2 ,…,X N of all N flow meters (15) which are connected with the control device (7) and correspond to the same SCAL type indirect cooling radiator, wherein flow data X 1 of the 1 st flow meter (15) corresponds to an electromagnetic regulating valve (14) of the 1 st path, flow data X 2 of the 2 nd flow meter (15) corresponds to an electromagnetic regulating valve (14) of the 2 nd path, and flow data X N of the N th flow meter (15) corresponds to an electromagnetic regulating valve (14) of the N th path; the control device (7) calculates an arithmetic average value of the N flow data based on the N flow data ; The control device (7) calculates the flow deviation value of the ith path, and the calculation formula is as follows: Wherein, the The flow deviation value of the ith path; is the flow data of the ith flowmeter (15); Will be Comparing the positive deviation threshold value with a preset positive deviation threshold value and a negative deviation threshold value; If it is If the opening of the electromagnetic regulating valve (14) of the ith path is reduced by a preset regulating step length until the opening reaches a preset minimum opening, generating and sending out a command by the control device (7) If the opening of the ith electromagnetic regulating valve (14) is smaller than or equal to the negative deviation threshold value, the control device (7) generates and sends out a command, and the opening of the ith electromagnetic regulating valve (14) is increased by a preset regulating step length until the preset maximum opening is reached; After the flow data of all the flowmeters (15) are judged and regulated, the control device (7) waits for a second preset time period, and then starts the flow data reading and regulation of the next round to form a closed-loop control cycle.

Description

Automatic water distribution device and method for water collection tank at bottom of radiator of SCAL type indirect cooling system Technical Field The invention belongs to the technical field of chemical corrosion prevention, and relates to an automatic water distribution device and method for a water collection tank at the bottom of a radiator of a SCAL type indirect cooling system. Background The SCAL indirect cooling system is a mainstream radiator structure adopted in a newly-built thermal power generating unit, the unit radiator is made of 1050A pure aluminum, circulating water flows through an aluminum pipe with the wall thickness of 1mm in operation, aluminum fins are wrapped outside the aluminum pipe, and the circulating water is cooled through air. During the operation of the system, the problem of corrosion of the aluminum pipe orifice of the radiator always plagues the type of indirect cooling system. The SCAL type indirect air cooling system adopts a surface condenser, and the radiator is arranged in a vertical mode. In the running process of the system, circulating water enters the water side of the surface condenser to exchange heat through the surface, heated circulating water is pumped to the indirect cooling tower by the circulating water, surface heat exchange is carried out between the circulating water and air through the air cooling radiator, and the circulating water returns to the condenser to cool the steam turbine to exhaust steam after being cooled, so that closed circulation is formed. As shown in fig. 1 to 3, the air-cooled radiator in the system is composed of a bottom water collection tank 102, an aluminum tube bundle 105 and a top water collection tank 101, and is made of 1050A pure aluminum. The aluminum tube bundle 105 includes, in order from left to right, an aluminum tube No. one 1051, an aluminum tube No. two, an aluminum tube No. nine 1059, an aluminum tube No. fifteen 10515, an aluminum tube No. nineteenth 10519, an aluminum tube No. twenty-two 10522, an aluminum tube No. twenty-three, an aluminum tube No. twenty-four 10524, an aluminum tube No. forty 10540. Next, the tube bundle 105 of aluminum tubes was 4 rows in total, in which the water flow direction was upward in two rows of aluminum tubes, referred to herein as the upper water aluminum tubes, and the water flow direction was downward in two rows of aluminum tubes, referred to herein as the lower water aluminum tubes, each row of aluminum tubes having 40 aluminum tubes. The bottom header tank 102 is divided into a hot water inlet 103 (water inlet side) and a cold water inlet 104 (water outlet side), and the middle is divided by a partition plate. The water inlet side of the bottom water collecting tank 102 has the function of distributing the circulating water conveyed by the pipeline to two rows of upper water aluminum pipes in the aluminum pipe bundle 105, after the circulating water is cooled, the circulating water is turned back downwards through the top water collecting tank 101, flows through the two rows of lower water aluminum pipes for continuous cooling, and the water in the lower water aluminum pipes flows into the circulating water pipeline after being collected by the water outlet side of the bottom water collecting tank 102, so that the whole heat dissipation and cooling process is completed. The hot water inlet 103 of the bottom water collecting tank 102 is partly shielded by a baffle, part of water flow is shielded by the baffle to change the flow direction, the water flow enters the water inlet side of the water collecting tank along the reducing above the water inlet, and the extension line of the reducing is opposite to the nine aluminum pipe 1059 and sixteen aluminum pipes, seventeen aluminum pipes and eighteen aluminum pipes, and the included angle between the positions of the nine aluminum pipes and the outlet of the water inlet pipe is about 45 degrees. A rubber sealing ring is arranged between the water collection tank and the aluminum pipe, the two are prevented from being in hard contact, and then the three parts are tightly pressed by the tightening strips outside the lower water collecting tank, so as to play a role in sealing. After the aluminum pipe orifice is corroded, once the aluminum pipe orifice is damaged beyond the sealing ring, circulating water can leak outwards. The prior research results show that the pipe orifices of the radiator aluminum pipes of a plurality of power plants all have corrosion phenomena with different degrees, the corrosion morphology is in the shape of valleys, teardrops and horseshoes, and the characteristic of typical scouring corrosion is realized. As shown in FIG. 3, the aluminum pipes with pipe orifice corrosion phenomenon are distributed near the two sides of the inlet of the bottom water collecting tank, the seventeen aluminum pipes and the eighteen aluminum pipes are corroded more seriously by the pipe orifices of the aluminum pipes at other posi