CN205782806U - Novel coal-based supercritical carbon dioxide boiler device - Google Patents

Abstract

The utility model discloses a novel coal-based supercritical carbon dioxide boiler device, which comprises a sequentially connected furnace, a horizontal flue and a tail flue, and a water-cooled wall and a wall-type reheater are sequentially arranged in the furnace along the direction of flue gas circulation. and panel superheater, a high-temperature reheater is arranged in the horizontal flue, and a low-temperature reheater, a primary air preheater and a secondary air preheater are arranged in the rear flue along the direction of flue gas circulation, and the rear flue The low-temperature superheater is arranged, and the low-temperature reheater and the low-temperature superheater are arranged side by side. The boiler device can be applied to the coal-based supercritical carbon dioxide Brayton cycle power generation system, and can effectively reduce the temperature of the boiler exhaust gas, and the efficiency of the boiler is high. .

Description

A new coal-based supercritical carbon dioxide boiler device

technical field

The utility model belongs to the field of advanced high-efficiency thermal power generation and relates to a novel coal-based supercritical carbon dioxide boiler device.

Background technique

Continuously improving the efficiency of generator sets is the eternal theme and goal of power industry research. For power generation companies, the higher the cycle efficiency of the system, the lower the energy consumption per unit of power generation, and the lower the corresponding energy consumption and pollutant emissions. For the traditional generator set with the steam Rankine cycle as the energy conversion system, if the power generation efficiency is increased to about 50%, the main steam parameters need to be increased to 700°C, which means that it takes a high economic cost and time cost to Research and development of new nickel-based superalloys. In order to avoid technical bottlenecks in materials, scholars from various countries have turned their attention to new power cycle systems in order to improve power generation efficiency. After a lot of preliminary research and demonstrations by scholars from various countries, the currently generally recognized supercritical carbon dioxide Brayton cycle is a new concept advanced power system with great potential. This is mainly because supercritical carbon dioxide has the characteristics of high energy density and high heat transfer efficiency. The high-efficiency power generation system of supercritical carbon dioxide Brayton cycle can reach the efficiency of conventional steam Rankine cycle of 700 ℃ in the temperature range of 620 ℃, and there is no need to develop new High-temperature nickel-based alloy, and the size of the equipment is smaller than the steam unit with the same parameters, and the economy is very good.

The characteristics of my country's energy endowment determine that coal-fired power generation will still be the main body of my country's power structure for a long time to come. Therefore, the development of large-scale coal-based supercritical carbon dioxide Brayton cycle high-efficiency power generation systems is very in line with my country's basic national conditions and has very broad applications prospect.

Although the supercritical carbon dioxide Brayton cycle power generation technology is already a public technology in the world, most of the supercritical carbon dioxide Brayton cycle power generation systems at home and abroad are aimed at new energy sources such as solar energy, but for traditional fossil energy sources, especially coal-based power generation systems. Novel systems are rarely involved. For the coal-based supercritical carbon dioxide Brayton cycle high-efficiency power generation system, since the entire circulation system includes a large number of heat recovery systems, the temperature of the supercritical carbon dioxide working medium at the boiler inlet generally exceeds 500 °C. For supercritical carbon dioxide boilers, if a conventional economizer is arranged at the tail of the boiler according to the heating surface layout method of the traditional steam boiler, the temperature rise of the working medium is usually only a few degrees Celsius due to the low heat transfer temperature and pressure at the economizer. Makes the layout of the heating surface unreasonable and poor in economy. In addition, the coal-based supercritical carbon dioxide Brayton cycle high-efficiency power generation system has a high inlet temperature of the working fluid and a high exhaust gas temperature at the tail, so how to reduce the exhaust gas temperature of the supercritical carbon dioxide boiler and improve the thermal efficiency of the boiler is also a crucial technical link .

Utility model content

The purpose of the utility model is to overcome the above-mentioned shortcomings of the prior art, and provide a novel coal-based supercritical carbon dioxide boiler device, which can be applied to a coal-based supercritical carbon dioxide Brayton cycle power generation system, and can effectively reduce boiler The higher the temperature of the exhaust gas, the higher the efficiency of the boiler.

In order to achieve the above object, the new coal-based supercritical carbon dioxide boiler device described in the utility model is used in a coal-based supercritical carbon dioxide Brayton cycle power generation system, including a furnace, a horizontal flue and a tail flue connected in sequence, and the furnace A water-cooled wall, a wall reheater and a panel superheater are arranged in sequence along the direction of flue gas circulation, a high-temperature reheater is arranged in the horizontal flue, and a low-temperature reheater is arranged in sequence along the direction of flue gas flow in the tail flue 1. Primary air preheater and secondary air preheater. A low-temperature superheater is arranged in the tail flue, and the low-temperature reheater and low-temperature superheater are arranged side by side;

The hot side outlet of the low temperature regenerator in the supercritical carbon dioxide Brayton cycle power generation system is divided into two paths, one of which is connected to the inlet of the precooler in the supercritical carbon dioxide Brayton cycle power generation system, and the other is connected to the supercritical carbon dioxide Brayton cycle power generation system. The inlet of the recompressor in the cycle power generation system is connected, and the outlet of the cold side of the high temperature regenerator in the supercritical carbon dioxide Brayton cycle power generation system is connected with the inlet of the water wall;

The outlet of the water wall is connected to the inlet of the low-temperature superheater, the outlet of the low-temperature superheater is connected to the inlet of the panel superheater, and the outlet of the panel superheater is connected to the inlet of the high-pressure turbine in the supercritical carbon dioxide Brayton cycle power generation system Connected;

In the supercritical carbon dioxide Brayton cycle power generation system, the outlet of the high-pressure turbine is connected to the inlet of the wall reheater, and the outlet of the wall reheater is connected to the inlet of the low-temperature reheater. The reheater communicates with the low-pressure turbine in the supercritical carbon dioxide Brayton cycle power generation system;

The air outlet of the primary air preheater is connected with the air inlet of the secondary air preheater, and the air outlet of the secondary air preheater is connected with the air inlet of the boiler.

An SCR denitration device is also arranged in the tail flue, and the SCR denitration device is located between the secondary air preheater and the primary air preheater.

The utility model has the following beneficial effects:

The boiler tail flue of the new coal-based supercritical carbon dioxide boiler device described in the utility model is arranged with a primary air preheater and a secondary air preheater, and the secondary air preheater reduces the flue gas temperature to that of the SCR denitrification reaction. The suitable temperature range is 350-400°C. The cooled flue gas enters the SCR denitrification device for denitrification reaction, and the flue gas after denitrification treatment enters the first-stage air preheater to exchange heat with the air, reducing the boiler exhaust gas temperature to At a certain level, on the one hand, it can effectively lower the exhaust gas temperature of the boiler and improve the thermal efficiency of the boiler; on the other hand, it can heat the combustion air of the boiler to above 500°C, increasing the temperature of the combustion air, which is beneficial to the ignition and combustion of pulverized coal, and at the same time, it is beneficial to the combustion of the boiler burner. The area creates a high-temperature and strong reducing atmosphere environment, thereby greatly reducing the formation of nitrogen oxides, thereby improving the power generation efficiency of the boiler.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Among them, 1 is water wall, 2 is low temperature superheater, 3 is panel superheater, 4 is wall reheater, 5 is low temperature reheater, 6 is high temperature reheater, 7 is secondary air preheater , 8 is the SCR denitrification device, and 9 is the primary air preheater.

detailed description

Below in conjunction with accompanying drawing, the utility model is described in further detail:

With reference to Fig. 1, the novel coal-based supercritical carbon dioxide boiler device described in the utility model is used in the coal-based supercritical carbon dioxide Brayton cycle power generation system, and comprises successively connected furnaces, horizontal flues and tail flues. A water-cooled wall 1, a wall reheater 4 and a panel superheater 3 are arranged in sequence along the direction of flue gas circulation, a high-temperature reheater 6 is arranged in the horizontal flue, and a low-temperature reheater is arranged in sequence in the tail flue along the direction of flue gas flow. Reheater 5, primary air preheater 9 and secondary air preheater 7, low temperature superheater 2 is arranged in the tail flue, low temperature reheater 5 and low temperature superheater 2 are arranged side by side; supercritical carbon dioxide Brayton cycle The outlet of the hot side of the low-temperature regenerator in the power generation system is divided into two paths, one of which is connected with the inlet of the precooler in the supercritical carbon dioxide Brayton cycle power generation system, and the other is connected with the recompressor in the supercritical carbon dioxide Brayton cycle power generation system The outlet of the high temperature regenerator in the supercritical carbon dioxide Brayton cycle power generation system is connected with the inlet of the water-cooled wall 1; the outlet of the water-cooled wall 1 is connected with the inlet of the low-temperature superheater 2, and the low-temperature superheater The outlet of panel superheater 3 is connected with the outlet of panel superheater 3, and the outlet of panel superheater 3 is connected with the inlet of the high-pressure turbine in the supercritical carbon dioxide Brayton cycle power generation system; the high pressure turbine in the supercritical carbon dioxide Brayton cycle power generation system The outlet of the turbine is connected to the inlet of the wall reheater 4, the outlet of the wall reheater 4 is connected to the inlet of the low-temperature reheater 5, and the outlet of the low-temperature reheater 5 is connected to the ultra- The low-pressure turbine in the critical carbon dioxide Brayton cycle power generation system is connected; the air outlet of the primary air preheater 9 is connected with the air inlet of the secondary air preheater 7, and the air outlet of the secondary air preheater 7 is connected with the The air inlets of the boilers are connected.

An SCR denitration device 8 is also arranged in the tail flue, and the SCR denitration device 8 is located between the secondary air preheater 7 and the primary air preheater 9 .

Supercritical carbon dioxide Brayton cycle power generation system includes precooler, main compressor, recompressor, low temperature regenerator, high temperature regenerator, boiler, high pressure turbine, low pressure turbine and generator; the heat of low temperature regenerator The side outlet is divided into two paths, one of which is connected to the inlet of the main compressor through the precooler, the outlet of the main compressor is connected to the cold side inlet of the low-temperature regenerator, and the other is connected to the inlet of the recompressor. The outlet of the recompressor and the outlet of the cold side of the low temperature regenerator are connected to the inlet of the cold side of the high temperature regenerator through pipes, and the outlet of the low pressure turbine is connected to the inlet of the hot side of the high temperature regenerator. The hot-side outlet of the heater is connected with the hot-side inlet of the low-temperature regenerator, and the output shaft of the low-pressure turbine is connected with the drive shaft of the generator; an SCR denitrification device 8 is also arranged in the tail flue, and the SCR denitrification device 8 is located on the second Between the primary air preheater 7 and the primary air preheater 9.

Concrete work engineering of the present utility model is:

The exhaust gas coming out of the hot side of the low-temperature regenerator is divided into two parts, one part is cooled by the pre-cooler and then enters the main compressor to boost the pressure, and then enters the cold side of the low-temperature regenerator for preheating and heating, and the other part directly passes through After boosting the pressure of the compressor, it merges with the outlet of the cold side of the low temperature regenerator and then enters the cold side of the high temperature regenerator. The working fluid output from the cold side of the high temperature regenerator enters the hot side of the low temperature regenerator. The working medium output from the hot side of the regenerator enters the water-cooled wall 1, and then passes through the water-cooled wall 1, the low-temperature superheater 2 and the panel superheater 3 in sequence; After working, the exhaust gas passes through the wall reheater 4, low temperature reheater 5 and high temperature reheater 6 in sequence, and then enters the low pressure turbine to do work. The hot side of the heater 4 is used to heat the new working fluid boosted by the recompressor.

In order to further reduce the exhaust gas temperature of the boiler and improve the thermal efficiency of the boiler, the utility model arranges a first-stage air preheater 9 and a second-stage air preheater 7 in the tail flue. The flue gas temperature is lowered to the appropriate temperature range for SCR denitration reaction, that is, 350°C to 400°C, and then the cooled flue gas enters the SCR denitrification device 8 for denitrification treatment, and the flue gas after denitration treatment enters the first-stage air preheater In step 9, the air entering the boiler is heated, so that the temperature of the heated air meets the furnace combustion and heat transfer requirements.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present utility model in detail. It should be understood that the above descriptions are only specific embodiments of the present utility model and are not intended to limit the present invention. For the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model shall be included in the protection scope of the utility model.

Claims (2)

1. a New type coal base supercritical carbon dioxide boiler plant, generates electricity for coal base supercritical carbon dioxide Brayton cycle In system, it is characterised in that include being sequentially connected logical burner hearth, horizontal flue and back-end ductwork, along flue gas circulation in burner hearth Direction has been sequentially arranged water-cooling wall (1), wall reheater (4) and pendant superheater (3), is disposed with high temperature reheating in horizontal flue Device (6), in back-end ductwork, the direction along flue gas circulation has been sequentially arranged low-temperature reheater (5), main air preheater (9) and two Level air preheater (7), is disposed with low temperature superheater (2) in back-end ductwork, low-temperature reheater (5) and low temperature superheater (2) and Arrangement is put；

In supercritical carbon dioxide Brayton cycle electricity generation system, the hot side outlet of cryogenic regenerator is divided into two-way, wherein a road with In supercritical carbon dioxide Brayton cycle electricity generation system, the entrance of precooler is connected, another road and supercritical carbon dioxide cloth Thunder pauses and recompresses the entrance of machine in cycle generating system and be connected, high temperature in supercritical carbon dioxide Brayton cycle electricity generation system The cold side outlet port of regenerator is connected with the entrance of water-cooling wall (1)；

The outlet of water-cooling wall (1) is connected with the entrance of low temperature superheater (2), and the outlet of low temperature superheater (2) is overheated with screen formula The entrance of device (3) is connected, the outlet of pendant superheater (3) and the height in supercritical carbon dioxide Brayton cycle electricity generation system The entrance of pressure turbine is connected；

The outlet of supercritical carbon dioxide Brayton cycle electricity generation system mesohigh turbine is connected with the entrance of wall reheater (4) Logical, the outlet of wall reheater (4) is connected with the entrance of low-temperature reheater (5), and the outlet of low-temperature reheater (5) is through high temperature again Hot device (6) is connected with the low pressure turbine in supercritical carbon dioxide Brayton cycle electricity generation system；

The air outlet slit of main air preheater (9) is connected with the air intake of secondary air preheater (7), and secondary air is pre- The air outlet slit of hot device (7) is connected with the air intake of boiler.

Novel coal supercritical carbon dioxide Brayton cycle electricity generation system the most according to claim 1, it is characterised in that There also is provided SCR denitration device (8) in back-end ductwork, it is empty with one-level that SCR denitration device (8) is positioned at secondary air preheater (7) Between air preheater (9).