CN204402591U - A kind of novel air cooling system - Google Patents

Abstract

The utility model discloses a new type of air-cooling system, which comprises a steam turbine, an air-cooling tower and a condensed water tank; an air-cooling condenser is arranged under the air-cooling tower, and the exhaust steam of the steam turbine is introduced into the air-cooling condenser through an exhaust pipe for direct cooling with cooling air. Heat exchange; the air-cooled condenser is connected to the condensate tank through the water header, and the condensed water is collected into the condensate tank through the water header; the outlet of the condensate tank is equipped with a condensate pump, and the condensate is boosted by the condensate pump Finally, it is sent to the shaft seal heater and enters the reheating system. The utility model takes into account the advantages of the direct air cooling system and the surface condensation type intercooling system, and effectively abandons their respective shortcomings. The utility model has the advantages of almost no power consumption, high heat exchange efficiency, high annual operating vacuum, strong environmental resistance ability, etc., effectively solves the problems faced by the current air-cooling unit, and improves the operating economy of the unit. The utility model can be applied to thermal power engineering, thermal power plants, air-cooling units to improve safety, economy, energy saving and consumption reduction, and the like.

Description

A new type of air cooling system

technical field

The utility model belongs to the field of heat energy exchange and aerodynamics, relates to a cold end system of a power station, in particular to a novel air cooling system.

Background technique

As an effective water-saving thermal power generation technology, the air-cooling technology of power plants is widely used in the power industry in areas where water resources are scarce. Looking forward to the future, the prospect of air-cooling technology for power plants is still promising. It can not only be used in water-scarce areas, but also has very high practical applications in terms of reducing water resource consumption and promoting sustainable use of water resources even in areas with abundant water resources. value.

There are three main types of air cooling systems currently used in power plants, namely direct air cooling systems, indirect air cooling systems with hybrid condensers (Heller type) and indirect air cooling systems with surface condensers (Harmon type).

In China, the direct air cooling system is the most widely used, followed by the surface condensing intercooling system, and finally the condensing intercooling system. The former two account for more than 98% of the installed capacity of air coolers. Decades of operating experience show that the water-saving advantages of the air-cooling system are quite obvious, but its disadvantages are also quite prominent: 1) In terms of direct air-cooling technology, there are high plant power consumption, low vacuum unit output during high temperature periods in summer, and sensitivity to environmental influences. 2) In terms of the surface condensing intercooling system, there are disadvantages such as high plant power consumption and low efficiency of two heat exchanges.

The direct air cooling system and the surface condensing intercooling system are comprehensively compared in terms of water saving effect, plant power consumption, environmental sensitivity, heat exchange efficiency, and annual operating economy, as follows:

1) Water-saving effect: the two are equivalent.

2) In terms of power consumption: the direct air cooling system uses an axial flow variable frequency fan. Although the frequency is adjusted according to the load of the unit and the inlet air temperature, the power consumption is still relatively large, and the power consumption rate is about 1% under full load; the table The circulating cooling water of the condensing intercooling system is supplied by two or three circulating water pumps. Although the circulating water pumps are optimized according to the load of the unit and the ambient temperature, the power consumption is still relatively large, which is basically the same as that of direct air cooling.

3) Environmental sensitivity: the direct air cooling system is more sensitive to the influence of ambient wind, and the operating back pressure of the unit varies greatly; the surface condensing intercooling system has a slower influence on the ambient wind, and the operating back pressure of the unit varies relatively small .

4) Heat exchange efficiency: The exhaust steam and cooling air in the direct air cooling system belong to one-time heat exchange, and the heat exchange efficiency is high, so the heat dissipation area is small; Transferred to the cooling air, the heat transfer efficiency is low, so the heat dissipation area is large.

5) Annual operation economy: The annual operating back pressure of the surface condensing intercooling system unit is lower than that of the direct air cooling system unit.

In summary, the direct air cooling system and the surface condensing intercooling system have obvious water saving effects, but the power consumption is also obvious. In addition, the direct air cooling system has high heat transfer efficiency, while the surface condensing intercooling system has poor environmental sensitivity and high annual operation economy. Under the national policy of energy conservation and emission reduction, and building a conservation-oriented society, how to effectively combine the advantages of the above two air-cooling forms, while discarding their disadvantages, and improving the advantages of air-cooling technology is becoming more and more important.

Utility model content

The purpose of this utility model is to solve the above problems and propose a new type of air-cooling system, which takes into account the advantages of both the direct air-cooling system and the surface-condensing intercooling system, while effectively discarding their respective shortcomings. The utility model has the advantages of almost no power consumption, high heat exchange efficiency, high annual operating vacuum, strong environmental resistance ability, etc., effectively solves the problems faced by the current air-cooling unit, and improves the operating economy of the unit. The utility model can be applied to thermal power engineering, thermal power plants, air-cooling units to improve safety, economy, energy saving and consumption reduction, and the like.

In order to achieve the above object, the technical solution adopted in the utility model is:

A new type of air-cooling system, including a steam turbine, an air-cooling tower and a condensed water tank; an air-cooling condenser is installed under the air-cooling tower, and the exhaust steam of the steam turbine is introduced into the air-cooling condenser through the exhaust pipe for direct heat exchange with the cooling air; the air-cooling The vaporizer is connected to the condensate tank through the water header, and the condensed water is collected into the condensate tank through the water header; a condensate pump is installed at the outlet of the condensate tank, and the condensate is boosted by the condensate pump and sent to the shaft seal Enter the heat recovery system after the heater.

The air cooling tower is a natural ventilation cooling tower, which is installed outside the factory building, and its cooling air is generated by the natural suction of the natural ventilation cooling tower.

The cooling tube bundles in the air-cooled condenser are steel tubes with aluminum fins, hot-dip galvanized.

The air-cooled condenser is vertically arranged on the lower periphery of the air-cooling tower.

The air-cooled condenser is a plurality of cooling units evenly arranged along the circumferential direction of the air-cooling tower, and the condensed water outlets of these cooling units are all connected to the condensed water tank through the water header.

The end of the exhaust pipe is provided with a steam distribution pipe connected to the air inlets of several cooling units, which distributes the exhaust steam of the steam turbine in the exhaust pipe to each cooling unit, and is cooled by the cooling air flowing through the air-cooled condenser.

The steam distribution pipe includes an annular steam distribution main pipe communicated with the exhaust pipe, and a branch pipe for leading the exhaust steam of the steam turbine into the corresponding cooling unit is provided at a corresponding position inside the annular steam distribution main pipe.

The air-cooled condenser is also provided with a vacuum system for extracting non-condensable gas from the air-cooled condenser.

The vacuum system includes a vacuum pipeline and a water ring vacuum pump. One end of the vacuum pipeline communicates with the air-cooled condenser, and the other end is connected to the water ring vacuum pump.

Each cooling unit of the air-cooled condenser includes a downstream part for guiding condensed water and a countercurrent part for cooperating with the vacuum system to draw away non-condensable gas, and the vacuum pipe is connected with each cooling unit The reverse flow part is connected.

Compared with the prior art, the utility model has the following beneficial effects:

The utility model is different from the traditional air-cooling unit (whether it is a direct air-cooling unit or an indirect air-cooling unit) in that it has neither a certain number of frequency conversion axial flow fans nor countless circulating water pumps; the cold end system has no power consumption equipment, so it is effective Save power for the plant; equipment such as condensate tanks and condensate pumps are installed near the lower part of the air cooling tower, so the anti-cavitation performance of the condensate pump is required to be high; since the air cooling tower is a certain distance from the main engine workshop, auxiliary equipment such as vacuum pumps can be installed in the tower nearby. The air-cooled condenser belongs to primary heat exchange, with high heat transfer coefficient; poor environmental sensitivity, and low back pressure during operation throughout the year. The utility model has neither a large number of axial flow fans of the direct air cooling system nor several circulating water pumps of the surface condensing intercooling system, effectively saves power consumption of the plant, and improves the operating economy of the air-cooling generating set as a whole.

Description of drawings

Fig. 1 is the schematic flow sheet of the utility model;

Fig. 2 is a schematic diagram of the steam distribution system of the present invention.

Among them, 1 is steam turbine; 2 is exhaust device; 3 is exhaust pipe and steam distribution pipe; 4 is natural ventilation cooling tower; 5 is air-cooled condenser; 6 is water header; 7 is vacuum pipe; 8 is Water ring vacuum pump; 9 is condensed water tank; 10 is condensed water pump; 11 is shaft seal heater; 12 is annular steam distribution main pipe; 13 is branch pipe.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail:

Referring to Fig. 1 and Fig. 2, the exhaust steam of the steam turbine of the utility model is introduced into the air-cooled condenser arranged on the lower periphery of the natural draft cooling tower through the exhaust pipe and the steam distribution pipe, and directly exchanges heat with the cooling air, and the condensed water after condensation It is collected into the condensate tank through the water header, and then enters the heat recovery system after being boosted by the condensate pump. The air-cooling tower is a natural ventilation cooling tower, which is installed at a certain position outside the factory building. The cooling air is generated by the natural suction of the air-cooling tower, and the air-cooling condenser is vertically arranged around the lower part of the air-cooling tower. The air-cooled condenser is evenly divided into several cooling units along the circumferential direction of the air-cooling tower. The schematic diagram (top view) of the steam distribution system is shown in Figure 2. The steam is distributed into the cooling unit by the steam distribution pipe, cooled by the cooling air flowing through the air-cooled condenser, and the condensed water is collected into the water header. Each cooling unit of the air-cooled condenser is provided with a forward flow part and a reverse flow part. The cooling tube bundle is steel tube with aluminum fins, hot-dip galvanized. The utility model is also provided with a vacuum system to extract the non-condensable gas in the air-cooled condenser. In addition, the condensed water tank of the utility model is arranged at the lower part of the air-cooled condenser of the air-cooling tower, and the condensed water pump is arranged at the lower part near the condensed water tank.

Application effect:

The biggest feature of this technology is that it saves not only the air-cooling fan of the direct air-cooling system, but also the circulating water pump of the surface condensing intercooling system, saving power consumption of the plant, and the power consumption of the plant is reduced by about 1%. The 600MW air-cooling unit is the main For example, the coal consumption rate of power supply is reduced by about 4g/(kW·h), which is obviously economical. In addition, the reduction of coal consumption rate means that the emission of nitrogen oxides and other pollutants under the same load has decreased, and the environmental benefits are significant.

The above content is only to illustrate the technical idea of the utility model, and cannot limit the protection scope of the utility model. Any changes made on the basis of the technical solution according to the technical idea proposed by the utility model all fall into the scope of the utility model. within the scope of protection of the claims.

Claims (10)

1. A novel air-cooling system is characterized in that: comprise steam turbine (1), air-cooling tower (4) and condensation water tank (9); The bottom of air-cooling tower (4) is provided with air-cooling condenser (5), steam turbine exhaust The steam is introduced into the air-cooled condenser (5) through the exhaust pipe (3) for direct heat exchange with the cooling air; the air-cooled condenser (5) is connected with the condensate tank (9) through the water header (6) The final condensed water is collected into the condensed water tank (9) through the water header (6); the condensed water pump (10) is installed at the outlet of the condensed water tank (9), and the condensed water is sent to the shaft after being boosted by the condensed water pump (10). Enter the heat recovery system after sealing the heater (11). 2. The novel air-cooling system according to claim 1, characterized in that: the air-cooling tower (4) is a natural draft cooling tower, which is arranged outside the workshop, and its cooling air is generated by the natural suction of the natural draft cooling tower. 3. The novel air-cooling system according to claim 1, characterized in that: the cooling tube bundle in the air-cooling condenser (5) is made of steel tubes with aluminum fins and hot-dip galvanized. 4. The novel air-cooling system according to claim 1, 2 or 3, characterized in that: the air-cooled condenser (5) is vertically arranged on the lower periphery of the air-cooling tower (4). 5. The novel air-cooling system according to claim 4, characterized in that: the air-cooled condenser (5) is a plurality of cooling units uniformly arranged along the circumferential direction of the air-cooling tower (4), and the condensation of these cooling units The water outlets are all communicated with the condensation water tank (9) through the water header (6). 6. The novel air-cooling system according to claim 5, characterized in that: the end of the exhaust pipe (3) is provided with a steam distribution pipe connected to the air inlets of several cooling units, and the exhaust pipe (3) The exhaust steam from the turbine is distributed to each cooling unit and cooled by the cooling air flowing through the air-cooled condenser (5). 7. The novel air-cooling system according to claim 6, characterized in that: the steam distribution pipe includes an annular steam distribution main pipe (12) communicated with the exhaust pipe (3), and the inner side of the annular steam distribution main pipe A branch pipe (13) for distributing exhaust steam from the steam turbine to a corresponding cooling unit is provided at the corresponding position. 8. The novel air-cooling system according to claim 1, 2 or 3, characterized in that: the air-cooled condenser (5) is also provided with a vacuum system for extracting non-condensable gas from the air-cooled condenser. 9. The novel air-cooling system according to claim 8, characterized in that: the vacuum system comprises a vacuum pipeline (7) and a water ring vacuum pump (8), and one end of the vacuum pipeline (7) is connected to the air-cooled steam The device (5) is connected, and the other end is connected to the water ring vacuum pump (8). 10. The novel air-cooling system according to claim 8, characterized in that: each cooling unit of the air-cooled condenser (5) includes a downstream part for guiding condensed water and a part for connecting with the vacuum pumping system Cooperate with the countercurrent part that sucks the non-condensable gas away, the vacuum pipe (7) communicates with the countercurrent part on each cooling unit.