CN104501624B - Evaporative type cooler and surface-type condensing system united power plant cooling system - Google Patents

Abstract

Evaporative type cooler disclosed by the invention and surface-type condensing system united power plant cooling system, include evaporative type cooler, and evaporative type cooler is connected with surface condenser and indirect cool tower by grid；Surface condenser connects and composes closed-loop path with water treatment facilities, boiler, steam turbine and generator combined unit successively by water pipe.Evaporative type cooler of the present invention and surface-type condensing system united power plant cooling system, when summer high temperature environment, use twin-stage to cool, it is ensured that the cooling effect of recirculated water, reduces system back pressure, improve steam turbine power generation efficiency.

Description

Power Plant Cooling System Combining Evaporative Cooler and Surface Condensing System

technical field

The invention belongs to the technical field of cooling systems, and in particular relates to a cooling system for a power plant combining an evaporative cooler and a surface condensing system.

Background technique

The power generation system cycle of a thermal power plant mainly includes boilers, steam turbines, generators, condensers and other components; the surface condensing system, also known as the surface condensing indirect air cooling system, is a thermal power plant that emerged according to the lack of water resources in Northwest my country. The power generation condensing system, the surface condensing system is mainly composed of an air cooling tower, a surface condenser, a circulating water pipeline and a circulating water pump; an important factor affecting the surface condensing system is the cooling capacity of the air cooling tower for circulating water, Most air cooling towers are designed with a cooling temperature difference of 10°C.

According to the distribution of coal resources in my country, coal resources are abundant in Northwest China. As a thermal power generation industry, the technical form of traditional wet-cooling cooling towers and the shortcomings of large water consumption limit their use in dry areas in Northwest China and areas lacking water resources. . In addition, the high-temperature weather that tends to occur in summer in Northwest China has a greater impact on the cooling effect of the air-cooling tower, resulting in a limited cooling effect of the air-cooling tower. Generally, the high-temperature environment in summer cannot achieve the desired effect of the design, resulting in an increase in the back pressure of the power generation system. The power generation load is limited, and it is often impossible to reach the full-load operation state, and the coal consumption of the power plant for power generation increases; it can be seen that cooling the circulating water is particularly important in high temperature seasons.

Evaporative cooling technology is a high-efficiency, water-saving, environmentally friendly and energy-saving cooling technology. According to the latent heat of vaporization when the cooling medium evaporates, the heat of the main equipment is removed to achieve the effect of cooling. Evaporative cooling equipment relies on the latent heat of vaporization to reduce the temperature of the unit's own circulating water to a sub-humid bulb temperature lower than the outdoor air wet bulb temperature; compared with the outdoor air temperature of the air-cooled cooling limit, the wet-cooled cooling limit of the outdoor air wet bulb temperature can be higher Effectively realize the cooling of the circulating water in the intercooling tower. In the northwestern region of my country, due to the large temperature difference between dry and wet bulbs, the driving force of evaporative cooling is relatively large, which is more conducive to the use of evaporative cooling technology.

For the surface condensing system of thermal power plants in Northwest my country, the evaporative cooler is used to realize the secondary cooling of the circulating water cooled by the intercooling tower, and to give full play to the advantages of the evaporative cooler in the dry area of the Northwest to improve the efficiency of high-temperature circulating water in summer. The cooling effect, reducing the back pressure of the power generation system, increasing the power generation load of the steam turbine, saving coal consumption for power generation, and increasing the economic benefits of power plant power generation have a certain promotion value.

Contents of the invention

The object of the present invention is to provide a cooling system for a power plant in which an evaporative cooler and a surface condensing system are combined. In the high temperature environment in summer, two-stage cooling is adopted to ensure the cooling effect of circulating water and reduce the system back pressure. The efficiency of steam turbine power generation is improved.

The technical solution adopted in the present invention is that the power plant cooling system combined with the evaporative cooler and the surface condensing system includes an evaporative cooler, and the evaporative cooler is connected with the surface condenser and the intercooling tower through the water pipe network. Connection; the surface condenser is sequentially connected with water treatment equipment, boiler, steam turbine and generator combined unit through water pipes to form a closed loop.

The present invention is also characterized in that,

The evaporative cooler includes a cooler shell, and an air inlet is provided on the opposite side walls of the cooler shell; a heat exchange module-filler composite cooling unit is arranged inside the cooler shell, and the heat exchange module-filler A standpipe type indirect evaporative cooling unit is installed on the left and right sides of the composite cooling unit; a water collector a is arranged above the heat exchange module-filler composite cooling unit, and the corresponding cooler shell above the water collector a There is an air outlet on the top wall of the body, and a cooling fan a (18) is arranged in the air outlet; a water collector b is arranged above the vertical pipe type indirect evaporative cooling unit, and the corresponding cooler shell above the water collector b An exhaust window is arranged on the top wall, and a cooling fan b is arranged inside the exhaust window.

The vertical pipe type indirect evaporative cooling unit includes a vertical heat exchange tube group, and a water spray device b is arranged above the vertical heat exchange tube group. It consists of downward spraying nozzles; a circulating water tank b is arranged under the vertical heat exchange tube group, and the circulating water tank b is connected to the spray pipe through the second water supply pipe; a wind is formed between the vertical heat exchange tube group and the circulating water tank b. The side wall of the cooler housing corresponding to the air duct is provided with a secondary air outlet.

The vertical heat exchange tube group is composed of multiple vertically arranged heat exchange tubes.

A circulating water pump b is arranged on the second water supply pipe.

Heat exchange module-packing composite cooling unit, including a heat exchange module, which is connected to the surface condenser and the intercooling tower through a water pipe network; a water spray device a is arranged above the heat exchange module, and the water spray The device a is composed of a water spray pipe and a plurality of downward spraying nozzles evenly arranged on the water spray pipe; below the heat exchange module, evaporative cooling fillers and a circulating water tank a are arranged in sequence, and the circulating water tank a passes through the first water supply pipe and the spray nozzle Water connection.

The water outlet of the heat exchange module is connected to the surface condenser through the circulating water pipe of the evaporative cooler, and the desalted water distribution pipe is connected to the circulating water pipe of the evaporative cooler. The water inlet of the heat exchange module is connected; the surface condenser is connected to the intercooling tower through the first water pipe, and the intercooling tower is connected to the desalted water distribution pipe through the second water pipe.

The heat exchange module is a heat exchange coil.

A circulating water pump a is arranged on the first water supply pipe.

The evaporative cooling filler is an inverted triangle filler.

The beneficial effects of the present invention are:

1. The cooling system for the power plant of the present invention adopts the circulating water cooled by the evaporative cooler to divert part of the intercooling tower for secondary cooling. The purpose is to ensure the cooling effect of the circulating water during the high temperature period in summer, so as to alleviate the decrease of the power generation load of the system caused by the increase in the back pressure of the surface condenser during the high temperature period in summer, thereby reducing the coal consumption of the power plant for power generation and improving the power generation efficiency.

2. The cooling system for a power plant of the present invention combines the standpipe type indirect evaporative cooling unit with the heat exchange module-packing compound cooling unit to form an evaporative cooler, precools the outdoor air through the standpipe type indirect evaporative cooling unit, and then passes The evaporative cooling filler in the thermal module-filler composite cooling unit further reduces the air temperature, and improves the heat exchange efficiency of the intercooling tower circulating water connected to the air and the heat exchange module in the high temperature environment in summer.

3. The cooling system for the power plant of the present invention adopts the combined form of indirect evaporative cooling technology and direct evaporative cooling technology to reduce the water temperature of the spray water in the evaporative cooler, and the temperature of the water outlet of the intercooling tower connected to the heat exchange module is relatively high, generally at In the temperature range where fouling is easy, the reduction of the room temperature of the shower water can make it difficult for the shower water to scale outside the heat exchange module, ensuring the service life of the evaporative cooler.

4. The evaporative cooler in the power plant cooling system of the present invention is provided with a water eliminator, which reduces the water consumption of the evaporative cooler, and the system transformation causes less safety hazards to the original system, and has certain feasibility .

Description of drawings

Fig. 1 is the structural representation of cooling system of power plant of the present invention;

Fig. 2 is a schematic structural view of the evaporative cooler in the cooling system of the power plant of the present invention.

In the figure, 1. Evaporative cooler, 2. Circulating water pipe entering evaporative cooler, 3. Circulating water pipe leaving evaporative cooler, 4. Water treatment equipment, 5. Boiler, 6. Combined unit of steam turbine and generator, 7 .Surface condenser, 8. Intercooling tower, 9. Demineralized water distribution pipe, 10. Circulating water pump b, 11. Circulating water tank b, 12. Evaporative cooling packing, 13. Circulating water pump a, 14. Circulating water tank a, 15. Water collector a, 16. Heat exchange module, 17. Water spray device a, 18. Cooling fan a, 19. Water collector b, 20. Cooling fan b, 21. Water spray device b, 22. Standpipe Heat exchange tube group, 23. the first water pipe, 24. the second water pipe.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The cooling system for a power plant combining the evaporative cooler and the surface condensing system of the present invention has a structure as shown in Figure 1, including an evaporative cooler 1, and the evaporative cooler 1 passes through the water pipe network and the surface condenser 7 It is connected with the intercooling tower 8; the surface condenser 7 is sequentially connected with the water treatment equipment 4, the boiler 5, the combined unit 6 of the steam turbine and the generator through water pipes to form a closed loop.

The evaporative cooler 1, whose structure is shown in Figure 2, includes a cooler shell, an air inlet is provided on the opposite side walls of the cooler shell, and a heat exchange module-filler compound is arranged in the cooler shell A vertical pipe-type indirect evaporative cooling unit is installed on the left and right sides of the heat exchange module-filler composite cooling unit; a water collector a15 is installed above the heat exchange module-filler composite cooling unit, The top wall of the corresponding cooler housing above the water heater a15 is provided with an air outlet, and a cooling fan a18 is arranged inside the air outlet, and a water eliminator b19 is arranged above each vertical pipe type indirect evaporative cooling unit, and the water eliminator An exhaust window is arranged on the top wall of the corresponding cooler housing above b19, and a cooling fan b20 is arranged in the exhaust window.

The vertical pipe type indirect evaporative cooling unit includes a vertical heat exchange tube group 22. The vertical heat exchange tube group 22 is composed of a plurality of vertically arranged heat exchange tubes; The device b21, the water spray device b21 is composed of a spray pipe and a plurality of downward spraying nozzles evenly arranged on the spray pipe; a circulating water tank b11 is arranged below the vertical heat exchange tube group 22, and the circulating water tank b11 passes through the second The water supply pipe is connected to the spray pipe, and the second water supply pipe is provided with a circulating water pump b10; an air duct is formed between the vertical heat exchange tube group 22 and the circulating water tank b11, and the side wall of the cooler shell corresponding to the air duct is provided with two Secondary outlet.

Heat exchange module-filler composite cooling unit, including heat exchange module 16, heat exchange module 16 is connected with surface condenser 7 and intercooling tower 8 through water pipe network; above heat exchange module 16, there is water spraying device a17 , the water spraying device a17 is composed of a water spray pipe and a plurality of downward spraying nozzles evenly arranged on the water spray pipe; below the heat exchange module 16, there are evaporative cooling fillers 12 and a circulating water tank a14 in sequence, and the circulating water tank a14 passes through the first A water supply pipe is connected with the water spray pipe, and a circulating water pump a13 is arranged on the first water supply pipe.

As shown in Figure 1, the water outlet of the heat exchange module 16 is connected to the surface condenser 7 through the circulating water pipe 3 of the evaporative cooler. The water distribution pipe 9 is connected to the water inlet of the heat exchange module 16 through the circulating water pipe 2 of the evaporative cooler; the surface condenser 7 is connected to the intercooling tower 8 through the first water pipe 23, and the intercooling tower 8 is connected through the second water pipe 24 On the desalinated water distribution pipe 9.

The heat exchange module 16 is a heat exchange coil.

The evaporative cooling filler 12 is an inverted triangle filler.

The working principle of the power plant cooling system combined with the evaporative cooler and the surface condensing system of the present invention:

The air first enters the evaporative cooler 1 through the air inlets on the two side walls of the evaporative cooler 1, and enters the two vertical pipe indirect evaporative cooling units under the drainage effect of the cooling fan a18, and each vertical pipe indirect evaporative cooling unit The air in the unit is divided into two parts, one part of the air flows outside the heat exchange tube, and the other part of the air flows through the heat exchange tube, and the water sprayed by the water spray device a17 exchanges heat with the air in the heat exchange tube to increase the air temperature. The heat exchange efficiency with water, the air in the heat exchange tube exchanges heat and moisture with water, the water evaporates on the surface of the water film attached to the inner wall of the heat exchange tube, absorbs the heat of the water film on the tube wall of the heat exchange tube, and cools the air outside the heat exchange tube , the air is in indirect contact with the water in the heat exchange tube, and the outdoor air outside the heat exchange tube is cooled by isohumidity; the pre-cooled air enters the heat exchange module-filler composite cooling unit, and when it passes through the evaporative cooling filler 12, it is connected with the water spray device The water under a17 spraying conducts heat and moisture exchange, part of the spraying water evaporates and vaporizes to take away the heat, the air is enthalpy cooled, and the temperature of the spraying water drops, and the isenthalpic cooled air flows outside the heat exchange module 16, and the cooled spraying water After falling back to the circulating water tank a14, under the action of the circulating water pump a13, it is sent to the water spraying device a17 through the first water supply pipe, and is sprayed by the water spraying device a17 to the outside of the heat exchange module 16, and flows countercurrently with the air from bottom to top. The heat exchange module 16 exchanges heat outside, and takes away the heat of the circulating water of the intercooling tower 8, so as to achieve the purpose of secondary cooling of the circulating water of the intercooling tower 8, and the air that absorbs heat passes through the water receiver a15 and then is discharged from the evaporative cooler 1; The circulating water after cooling down for the first time returns to the water treatment equipment of the power plant, and enters the boiler 5 after being treated to continue the power generation cycle.

Among them, the evaporative cooler 1 is installed on the ground, the heads of the circulating water pump a13 and the circulating water pump b10 are relatively low, and the spraying water circulation of the evaporative cooler 1 is small, and the cooling water and the air are exchanging heat External vaporization heat exchange of the module 16, the water consumption of the evaporative cooler 1 for showering is small, and the energy consumption for transportation is low.

The working process of the power plant cooling system combined with evaporative cooler and surface condensation system of the present invention is as follows:

1. During the high temperature period in summer: after entering the two air inlets of the evaporative cooler 1, the outdoor air with a relatively high temperature flows into the vertical pipe-type indirect evaporative cooling unit, and the air is divided into 22 places in the vertical heat exchange tube group. is two; part of the air flows through the heat exchange tube, and the other part of the air flows through the heat exchange tube, and the air entering the heat exchange tube is countercurrently exchanged with the uniform water film formed on the inner wall of the heat exchange tube by the water sprayed by the water spray device b22 Heat, cool the temperature of the water film on the inner wall of the heat exchange tube, and the air after the heat and humidity exchange in the heat exchange tube is treated by the water eliminator b19, and then discharged out of the evaporative cooler 1 through the exhaust window.

2. The wet pre-cooled air through the standpipe indirect evaporative cooler enters the heat exchange module-packing composite cooling unit, flows through the evaporative cooling packing 12 and the water sprayed by the water spray device a17 in the evaporative cooling packing The surface of 12 conducts heat and moisture exchange, and the water film on the surface of evaporative cooling packing 12 evaporates, absorbing the heat of air and water, cooling the air and water, the cooled air flows through the heat exchange module 16, and the cooled water flows back to the to the circulating water tank a14.

The cooling water is sent to the water spraying device a17 through the first water supply pipe under the action of the circulating water pump a13 for spraying, and performs countercurrent heat exchange with the air outside the heat exchange module 16 to absorb the heat of the circulating water of the intercooling tower 8, The air is finally discharged from the evaporative cooler 1 after being processed by the water eliminator a15 at the lower part of the cooling fan a18, and the shower water continues to fall into the evaporative cooling filler 12 for heat exchange, and finally falls back into the circulating water tank a14.

3. The circulating water cooled by the heat exchanger of the intercooling tower 8 enters the heat exchange module 16 through the circulating water pipe 2 of the evaporative cooler. The cooler circulating water pipe 3 is sent out of the evaporative cooler 1, and then sent back to the boiler 5 of the power plant to continue to complete the power generation cycle.

The power plant cooling system of the present invention combines the evaporative cooler with the surface condensing system of the power plant, adopts the evaporative cooling technology of the evaporative cooler, and passes the circulating water cooled by the intercooling tower through the evaporative cooler. In the high temperature environment in summer, two-stage cooling is used to ensure the cooling effect of circulating water. It can also reduce the back pressure of the system in high temperature environment, improve the efficiency of steam turbine power generation, and reduce the coal consumption of power generation. In thermal power plants in Northwest my country It has a good application prospect in the intercooling system.

Claims (5)

1. evaporative type cooler and surface-type condensing system united power plant cooling system, it is special Levying and be, include evaporative type cooler (1), described evaporative type cooler (1) passes through water Pipe network is connected with surface condenser (7), indirect cool tower (8)；

Described surface condenser (7) by water pipe successively with water treatment facilities (4), boiler (5), steam turbine and generator combined unit (6) connect and compose closed-loop path；

Described evaporative type cooler (1), includes cooler casing, described cooler casing phase To two side on be each provided with an air inlet；

Heat exchange module-packing composite cooling unit it is provided with in described housing of cooler body, described The arranged on left and right sides of heat exchange module-packing composite cooling unit is each provided with between a vertical pipe type Connect evaporation cooling unit；

Described heat exchange module-packing composite cooling unit be provided above water collection device a (15), It is provided with exhaust outlet, institute on the cooler casing roof that described water collection device a (15) top is corresponding Cooling blower a (18) it is provided with in stating exhaust outlet；

The top of described vertical pipe type indirect evaporating-cooling unit is provided with water collection device b (19), It is provided with ventilation window, institute on the cooler casing roof that described water collection device b (19) top is corresponding Cooling blower b (20) it is provided with in stating ventilation window；

Described vertical pipe type indirect evaporating-cooling unit, includes vertical heat exchanging pipe group (22), institute That states vertical heat exchanging pipe group (22) is provided above liquid distribution b (21), and described trickle fills Put b (21) by shower and to be uniformly arranged on the nozzle of multiple downward sprays on shower and form；

The lower section of described vertical heat exchanging pipe group (22) is provided with cyclic water tank b (11), described Cyclic water tank b (11) is connected with shower by the second feed pipe；

Air channel, wind is formed between described vertical heat exchanging pipe group (22) and cyclic water tank b (11) It is provided with overfiren air port on the housing of cooler body sidewall that road is corresponding；

Described heat exchange module-packing composite cooling unit, includes heat exchange module (16), institute State heat exchange module (16) by grid and described surface condenser (7), indirect cool tower (8) Connect；

Described heat exchange module (16) be provided above liquid distribution a (17), described trickle Device a (17) is by sparge pipe and is uniformly arranged on the nozzle sets of multiple downward sprays on sparge pipe Become；

The lower section of described heat exchange module (16) is disposed with evaporation cooling filler (12) and follows Ring water tank a (14), described cyclic water tank a (14) is connected with sparge pipe by the first feed pipe；

The outlet of described heat exchange module (16) is by going out evaporative type cooler circulating water pipe (3) Be connected with surface condenser (7), described in go out and connect on evaporative type cooler circulating water pipe (3) Being connected to demineralized water water distributor (9), described demineralized water water distributor (9) cools down by entering vaporation-type Device circulating water pipe (2) is connected with the water inlet of heat exchange module (16)；

Described surface condenser (7) is connected with indirect cool tower (8) by the first water pipe (23), Described indirect cool tower (8) is connected with demineralized water water distributor (9) by the second water pipe (24)；

Described evaporation cooling filler (12) is the filler of inverted triangle body shape.

Power plant the most according to claim 1 cooling system, it is characterised in that described vertical Formula set of heat exchange tubes (22) is made up of the many heat exchanger tubes being vertically arranged.

Power plant the most according to claim 1 cooling system, it is characterised in that described Water circulating pump b (10) it is provided with on two feed pipes.

Power plant the most according to claim 1 cooling system, it is characterised in that described in change Thermal modules (16) is heat exchange coil.

Power plant the most according to claim 1 cooling system, it is characterised in that described Water circulating pump a (13) it is provided with on one feed pipe.