System and method for preparing ammonia through urea hydrolysis based on peak regulation heat storage of coal-fired unit of thermal power plant

Abstract

The invention discloses a system and method for preparing ammonia through urea hydrolysis based on peak regulation heat storage of a coal-fired unit of a thermal power plant. The system comprises the coal-fired unit, a heat storage unit and a urea hydrolysis ammonia production unit, wherein the coal-fired unit comprises a boiler, an SCR denitration unit arranged in the boiler, a steam turbine connected to an outlet of a steam coil of the boiler and a generator; an NOx concentration detection probe is arranged at an inlet of the SCR denitration unit; the heat storage unit comprises a heat storage medium, a heat storage loop and a heat release loop; the inlet end of the heat storage loop is connected with a steam outlet of the steam turbine, the outlet end of the heat storage loop is connected with a steam-water system of a generator set, the inlet end of the heat release loop is connected with an outlet of a heat-conducting oil cold tank, and the outlet end of the heat release loop is connected to an inlet of a heat-conducting oil hot tank. A heat source inlet of the urea hydrolysis ammonia production unit is connected with the outlet of the heat-conducting oil hot tank, a heat source outlet is connected with the inlet of the heat-conducting oil cold tank, and an ammonia gas outlet is connected with the SCR denitration unit; the signal output end of the NOx concentration detection probe is connected with the outlet of the heat conduction oil hot tank and a control valve of a urea solution inlet of the urea hydrolysis ammonia production unit.

Description

technical field [0001] The invention relates to the technical field of flue gas denitrification, in particular to a urea hydrolysis ammonia production system and method based on peak regulation and heat storage of coal-fired units in thermal power plants. Background technique [0002] With the rapid increase of installed capacity of my country's power grid, the mismatch between power supply and demand has become increasingly serious, and the phenomenon that residents' power consumption is far less than the power supply makes power plants' coal-fired units often operate in deep peak-shaving and low-load operation. In addition, with the continuous development of new energy power generation technology, the grid connection space of coal-fired units has been occupied on a large scale. In addition, new energy sources such as wind energy have anti-peaking characteristics such as large volatility and poor stability, which further brings huge challenges and restrictions to the peakin...

AI Technical Summary

Problems solved by technology

The urea hydrolysis ammonia production technology has the advantages of high conversion rate, less by-products, and high safety. The conventional urea hydrolysis ammonia production technology extracts low-grade steam from the steam turbine as a heat source, and the steam is pumped and used immediately, which has a certain impact on the power generation efficiency of the unit. influences

In addition, the convective heat transfer coefficient of high-temperature steam is smaller than that of heat transfer oil. When steam is used as the heat source, the urea hydrolysis reactor has a large volume and is not convenient for layout.

At present, there are few technologies that efficiently combine the residual gas and electricity of coal-fired units during deep peak regulation with the ammonia production technology of selective catalytic reduction flue gas denitrification. The existing technologies are complex in design, cumbersome in operation, and low in utilization rate. advanced questions

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