A Method of Improving Waste Heat Utilization of Steam Turbine Unit

Abstract

The invention discloses a method for improving waste-heat utilization of a steam turbine unit. The method is based on a direct air cooling unit and a wet cooling unit which are concomitant in a power station, a heat exchanger is additionally arranged in a steam exhaust device of the direct air cooling unit, fed water of the wet cooling unit is led to the heat exchanger arranged in the steam exhaust device of the direct air cooling unit to conduct circulation flowing, and high-temperature steam in the steam exhaust device of the direct air cooling unit is used for heating the fed water of the wet cooling unit. The method is reasonable and effective, waste heat of the direct air cooling unit is reliably used, the energy consumption of the direct air cooling unit and the wet cooling unit is reduced, the output of the wet cooling unit is improved, the power generation cost of the power station is greatly reduced, energy conservation and environment protection are achieved, the earnings are greatly and reliably improved.

Description

technical field [0001] The invention relates to an operation method of a steam turbine unit, in particular to a method for improving waste heat utilization of the steam turbine unit. Background technique [0002] At present, the utilization measures for the waste heat of exhaust steam at the cold end of the steam turbine unit are mainly heating the heating network during the heating period, so as to reduce the loss of exhaust heat at the cold end of the steam turbine unit and improve the thermal efficiency of the power plant. However, the waste heat utilization of this steam turbine unit is realized based on the existence of heat supply demand. If there is no heat supply demand for a pure power generation steam turbine unit, the cold end exhaust heat of the steam turbine unit cannot be utilized due to the lack of demand objects. As a result, the exhaust steam at the cold end of the steam turbine unit is wasted, the thermal efficiency of the power plant is low, and the cost o...

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Problems solved by technology

[0004] Through the process flow of the direct air-cooled unit, it can be clearly seen that the temperature of the steam discharged to the air-cooled condenser through the exhaust device is very high, the heat load of the air-cooled condenser is high, and the steam condensation efficiency is low, so it is necessary to increase the axial flow cooling fan In order to increase the air flow to cool the air-cooled condenser, this not only makes a large amount of unused waste heat exhausted from the cold end of the steam turbine unit directly discharged into the atmosphere, causing waste and serious thermal pollution to the atmosphere , which is not conducive to energy saving and environmental protection, and the high-efficiency work of the axial flow cooling fan will inevitably lead to a substantial increase in power consumption of the power plant and increase operating costs

Through the technological process of the wet cooling unit, it can be clearly seen that the temperature of the feed water formed after the condensation of the wet cooling tower is very low, and it is necessary to increase the steam extraction to heat the feed water at the final low-pressure heater, and then send the heated feed water to the high-pressure heater. Heating, which not only wastes the high-quality steam of the wet-cooling unit, reduces the output of the wet-cooling unit, but also increases the energy consumption of the wet-cooling unit, which greatly increases the operating cost

[0005] To sum up, in view of the fact that direct air-cooled units and wet-cooled units belong to pure power generation steam turbine units without heat supply demand, there has not been a technology to utilize the waste heat of the exhaust steam at the cold end in the prior art, and their exhaust steam exhaust at the cold end The heat cannot be used, it is continuously wasted, the thermal efficiency of the power plant is low, and the cost of power generation is high

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