Thermal power plant combined ventilation direct air cooling system

Abstract

The present invention disclose a thermal power plant combined ventilation direct air cooling system, including hyperbolic air cooling tower, a plurality of air intake channels arranged along the circumferential direction on outboard of the air cooling tower bottom, and the air intake channel is cylandrical structure of open outer end and inner end communicated with the air cooling tower internal, inside each air intake channel is arranged with air condensator unit connected with steam turbine exhaust pipe and condensation water collecting pipe, outside air exchange heat with the air condensator unit in the air intake channel and expel from the air cooling tower. The invention sets air intake channel and the matching hyperbolic air cooling tower, and makes full use of pumping action of the air cooling tower to airflow in the premise of assuring fan activity, greatly reduce the affect if ambient wind velocity, wind direction, temperature and assure reliable and stable cooling to the heat dissipating finned tube, and provide guarantee to power generating plant stable power generation. The invention provides a feasible, optimized technology approach for present thermal power plant alteration.

Description

technical field [0001] The invention relates to the technical field of thermal power plant cooling, in particular to a combined ventilation direct air cooling system. Background technique [0002] The direct air cooling system is one of the cooling methods for the steam exhausted from the steam turbine in the existing thermal power plant. The steam discharged from the steam turbine is sent to the finned tube bundle of the air-cooled condenser arranged outdoors through the exhaust pipe, and the cooling air flows outside the finned tube to condense the exhaust steam in the tube, and the condensed water obtained is sent to the heating system for recycling. Such as figure 1 As shown, the direct air cooling system usually consists of several condenser units, and each condenser unit is composed of a finned tube bundle and a large-diameter axial flow fan. Below the finned tube bundle, the finned tube bundle is directly air-cooled by a fan (also known as the air-cooled island vent...

AI Technical Summary

Problems solved by technology

Since each condenser unit is very large, for example, the diameter of the fan is usually 9 meters, and the erection height is often as high as tens of meters. For a 600,000-kilowatt generating set, 64 sets of condenser units are required to condense the steam. Therefore, the direct air-cooling system in a thermal power plant needs to occupy a huge space, and the high-rise condenser unit and its cooling fan also bring great difficulties to the daily maintenance of the equipment

[0003] In addition, the condenser unit in the existing direct air cooling system is directly installed outdoors, and is greatly affected by environmental factors such as external temperature, wind direction, and wind speed during operation.

When the ambient temperature is high, the cooling efficiency of the condenser is low, and when the ambient temperature is low, the cooling efficiency of the condenser is high. In this way, direct air cooling is used in areas with a large temperature difference between day and night, which will cause large fluctuations in the work of the steam turbine in the power plant, which will affect power generation. The stable power generation of the plant

Similarly, the wind direction and wind speed will also affect the cooling efficiency of the condenser and cause fluctuations in the operation of the steam turbine, resulting in instability of the power generation of the power plant

[0004] In addition, the surface of the finned tube bundle of the condenser exposed to the air is easy to accumulate dust, which affects its effective heat dissipation.

[0005] Problems in the ventilation mode of the air-cooled island: 1. The operation is not stable due to the strong influence of the wind; 2. The phenomenon of hot air backflow is relatively serious; 3. The energy consumption of the fan is high; It is easy to accumulate dust, which affects the heat dissipation efficiency

5. In the case of sunshine, the exposed condenser fin tube bundle absorbs the sun's radiant heat, and the heat carried away by the heated air through the condenser fin tube bundle contains the sun's radiant heat, thereby reducing the heat dissipation efficiency

6. The equipment is high from the ground, making maintenance and cleaning difficult

[0006] When the above problems are mild, they will increase the coal consumption of power generation and affect the stable power generation. In severe cases, the unit will trip and affect the operation of the power grid.

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