Brown coal drying power generating system capable of recycling water in coal and implementation method of brown coal drying power generating system

Abstract

The invention discloses a brown coal drying power generating system capable of recycling water in coal and an implementation method of the brown coal drying power generating system. The brown coal drying power generating system comprises a boiler, a steam turbine, a water feed pump, a condenser, a coal mil, a brown coal drying device, a device for recycling the water in the coal, a raw coal bunker, a low-pressure heater, a deaerator, a high-pressure heater, a condensate pump and a steam-water mixer. The brown coal drying device is connected with the device for recycling the water in the coal, the raw coal bunker, the low-pressure heater, the deaerator, the high-pressure heater, the condensate pump, the steam-water mixer, the boiler, the steam turbine, the water feed pump, the condenser and the coal mill. Operation of a large-capacity brown coal power generating set is achieved by integral design of the brown coal drying device and the boiler and combination of the device for recycling the water in the coal and the steam turbine.

Description

technical field [0001] The invention relates to the technical field of coal-fired thermal power generation, in particular to a lignite drying power generation system for recovering water in coal and an implementation method thereof. Background technique [0002] my country has relatively large reserves of lignite, and the proven storage capacity is about 210 billion tons, accounting for 13% of the national coal reserves. This type of coal has high water content (35%-50%), low calorific value, high volatile content, and is prone to spontaneous combustion. Large-scale development and utilization and conversion and utilization as raw materials are subject to relatively large restrictions. In order to make efficient use of lignite, the most economical method is to dry and dehydrate it first. In the power industry, by reducing the moisture in lignite and increasing the calorific value, the investment in subsequent system equipment (milling, boilers, desulfurization, dust removal,...

AI Technical Summary

Problems solved by technology

The coal is not dried before entering the coal mill. Due to the high moisture content, the loss of boiler exhaust smoke is large, the thermal efficiency is low, the economy is limited, and the emission of greenhouse gases is also large.

In addition, the calorific value of lignite is low. In order to achieve the same installed capacity, the volume of the boiler body becomes larger, the cost is expensive, the selection of boiler auxiliary equipment is large, and the plant power consumption rate is high.

[0004] In terms of lignite power generation technology, the Chinese utility model patent with the publication number CN101881191A discloses a thermal power generation system based on high-moisture lignite pre-drying and upgrading and recovery technology. The lignite pre-drying device provided by it is a traditional lignite dryer. The thermal effect is poor, the floor area is large, the noise is high during operation, and the energy waste is serious; another Chinese utility model patent with the publication number CN102944024A discloses a lignite thermal power generation system. Water vapor is recovered through direct heat exchange between water and steam, resulting in the mixing of recycled water and cooling water, and the pollution carried by the steam is deposited into the water, causing water treatment air accidents

In addition, the biggest feature of these two patents is that lignite is dried and then transported to the boiler room for power generation. It is a simple connection between lignite drying and power plant power generation, and the project cost is high. Large, high energy consumption for conveying equipment

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