Hot-pressing type ultra supercritical unit number-zero high-pressure heater and switching system thereof

Abstract

The invention provides a hot-pressing type ultra supercritical unit number-zero high-pressure heater, a switching system thereof and a novel technological process for improving the low-load running economical efficiency of thermal power generating units. A hot press, the number-0 high-pressure heater and related valves and pipe fittings connected with the hot press and the number-0 high-pressure heater are used as core parts of the technological process, and all other devices are devices of existing units. The technological process has a main effect of adding a level of regenerative heating to an existing steam extraction heat recovery system, the thermal economical efficiency of the units under low loads is improved, the smoke temperature of an outlet of an economizer can be effectively improved, and the removal efficiency of a denitration system under the low-load work condition is ensured. In addition, due to input of the set of technological process, the air temperature can be effectively increased, and impact generated on the unit thermal economical efficiency and the boiler safety under the high-pressure cut-off work condition can be relieved.

Description

technical field [0001] The invention relates to a regenerative heating system of a power plant. In particular, it relates to a hot-press type ultra-supercritical unit zero high-pressure generator and its switching system. Background technique [0002] In recent years, the average annual utilization hours of thermal power units in my country has continued to decrease, and the load rate of most units is less than 70%. Under low load conditions, the thermal economy and safety of the units will decline significantly. Improve the heat recovery system to improve the thermal economy of the unit under low load conditions. From the perspective of thermodynamics, the more heat recovery stages of the unit, the higher the thermal efficiency. However, due to factors such as the structure of the steam turbine, the heat recovery stages are also subject to certain restrictions. At present, 7-9 heat recovery stages are often used. . The Chinese patent application number 201210047719.1 disc...

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Problems solved by technology

[0004] 1. The efficiency of the unit under low load conditions is lower than the design value;

[0005] 2. Under low load conditions, the flue gas temperature at the outlet of the economizer is low, which cannot guarantee the denitrification efficiency

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