CN205372701U - Waste heat of boiler flue gas circulation heat supply system - Google Patents

Abstract

The utility model relates to a boiler flue gas waste heat circulation heating system, which is characterized in that the heat supply system includes an intake pipe, a blower, a dust removal device, a boiler flue gas waste heat heating box, an air outlet pipe, a cold water pipe, a chimney, a drying device, a hot water Circulating heating pipes, hot water tanks, hot water pipes, catalytic heating devices and water outlet pipes; the blower is equipped with a catalyst, the air inlet end of the blower is connected to the air inlet pipe, the air outlet is connected to one end of the dust removal device, and the boiler smoke There is a curved flue gas heating pipe in the gas waste heat heating box, one end of the curved flue gas heating pipe is connected to the other end of the dust removal device, and the other end of the curved flue gas heating pipe is connected to one end of the outlet pipe; boiler flue gas waste heat The water inlet of the heating box is connected to one end of the cold water pipe, and the water outlet is connected to one end of the water outlet pipe; the catalytic heating device is provided with a catalytic case, and in the catalytic heating device, the outer surface of the catalytic case is surrounded by a hot water circulation Heat the pipes.

Description

Boiler flue gas waste heat circulation heating system

technical field

The utility model belongs to the technical field of heating systems, in particular to a boiler flue gas waste heat circulation heating system.

Background technique

The two major losses in thermal power plants are cold source loss and exhaust heat loss. The loss of cold source directly affects the heat efficiency of the cycle. For ordinary generator sets, the loss of cold source depends on the design parameters of the unit. The exhaust heat loss is the largest among all heat losses of power plant boilers. The exhaust heat loss of modern power plant boilers is generally about 4% to 8%. An important factor affecting the heat loss of exhaust gas is the exhaust gas temperature. According to statistics, in a thermal power plant, the exhaust heat loss of the boiler accounts for 60% to 70% of the total heat loss of the boiler. Every time the exhaust gas temperature rises by 10°C, the boiler efficiency will drop by 0.6-1.0%, and the standard coal consumption will rise by 1.2-2.4g/(kW·h), thus causing a huge waste of coal for electricity. At present, the high exhaust gas temperature has become one of the main reasons affecting the boiler efficiency. In order to reduce low-temperature corrosion, the exhaust gas temperature of the boiler is generally designed at 130-150 °C, but often due to the influence of ash, corrosion, air leakage and combustion conditions on the heated area of the tail, the actual operating exhaust gas temperature is higher than the design value by more than 20 °C. Therefore, reducing the exhaust gas temperature has important practical significance for saving fuel, improving unit efficiency and reducing pollution.

However, the existing recovery device will lead to the existence of waste heat, and the recovery is not comprehensive, and there is a lot of waste when the waste heat is recovered. For example, the ZSHH-A heat pipe waste heat recovery device (air-water), the lower part is the flue, and the upper part is the water tank. There is a partition in the middle, a safety valve, a pressure gauge, and a temperature gauge interface on the top, and the water tank has an inlet and outlet and a sewage outlet. The disadvantage is that there is only water and heat exchange during the recovery process, and the part contained in the flue gas is not completely released. The heat energy of the heat pipe cannot be utilized, resulting in waste of heat energy. At the same time, this process cannot realize secondary recovery, and at the same time, it lacks the treatment of exhaust gas; The baffle separates the passages on both sides, the heat pipe is a full-finned tube, and a single heat pipe can be replaced. The exhausted flue gas contains some heat, and the temperature of the waste heat recovery cannot be monitored anytime and anywhere, and the water temperature can only be controlled by adjusting the amount of flue gas in and out; the incineration of the tail gas recovery system of Nanjing Yire Zonglian Technology Co., Ltd. The furnace has a unique structure of zoom tube type, the flame distribution is uniform, the air flow is violently disturbed, and the material is completely burned. The amount of recovered steam is low, which cannot meet the production demand.

Utility model content

Aiming at the deficiencies of the prior art, the technical problem to be solved by the utility model is to provide a boiler flue gas waste heat circulation heating system. The system improves the existing equipment, carries out catalytic combustion treatment on the flue gas, and adopts a variable cross-section design for the curve pipe turning, which significantly prolongs the heat exchange time and enables the hot air and cold water to fully exchange heat, with high energy utilization and heat exchange. The high temperature difference significantly improves the heating effect, avoids energy waste, saves costs, and is more energy-saving and environmentally friendly.

The technical scheme adopted by the utility model to solve the above-mentioned technical problems is to provide a boiler flue gas waste heat circulation heating system, which is characterized in that the heating system includes an intake pipe, a blower, a dust removal device, a boiler flue gas waste heat heating box, Air outlet pipe, cold water pipe, chimney, drying device, hot water circulation heating pipe, hot water tank, hot water pipe, catalytic heating device and water outlet pipe; said blower is provided with a catalyst, and the air inlet end of the air blower is connected to the air inlet pipe, The gas outlet is connected to one end of the dust removal device. The boiler flue gas waste heat heating box is provided with a curved flue gas heating pipe. One end of the curved flue gas heating pipe is connected to the other end of the dust removal device. The curved flue gas heating pipe is The other end is connected to one end of the gas outlet pipe; the water inlet of the boiler flue gas waste heat heating box is connected to one end of the cold water pipe, and the water outlet is connected to one end of the water outlet pipe; Inside, the outer surface of the catalytic box is surrounded by a hot water circulation heating pipe; the bottom of the catalytic box is connected to the other end of the outlet pipe, and the upper part of the catalytic box is provided with a catalyst adding unit; the hot water circulating heating pipe is a one-way curve There are fins on the outside of the hot water circulation heating pipe, and a wire mesh composite tube core is used inside the hot water circulation heating pipe. The other end of the pipeline is connected, the other end of the hot water circulation heating pipeline is connected to the hot water inlet of the hot water tank installed in the room through the hot water pipeline, and the cold water outlet of the hot water tank is connected to the other end of the cold water pipeline. A temperature detection and display unit is provided inside the box; the drying device is arranged above the catalytic heating device, the lower part of the drying device is connected to the catalyst adding unit of the catalytic heating device through an exhaust pipe, and the upper part of the drying device is connected to the chimney.

Compared with the prior art, the beneficial effects of the utility model are:

1. The utility model uses a blower to introduce the flue gas generated in the thermal power plant into the dust removal device for dust removal. The flue gas after dust removal enters the boiler flue gas waste heat heating box to heat the cold water in the box, and then the flue gas Enter the catalytic box in the catalytic heating device, react with the catalyst, remove sulfur dioxide, nitrogen monoxide and other harmful gases in the flue gas, then dry the reacted flue gas by the drying device, and finally discharge it from the chimney. The whole process The cold water is heated by the waste heat of the boiler flue gas and the heat generated by the catalytic reaction of the flue gas, which greatly saves energy, has high heat exchange temperature difference, good heating effect, and can effectively remove harmful substances in the flue gas. , Purify flue gas and protect the environment.

2. In the utility model, the hot water tank is introduced into the boiler flue gas waste heat heating box by the cold water pipeline for heating, and the heated water enters the hot water circulation heating pipeline in the catalytic heating device through the water outlet pipeline, and utilizes the catalytic reaction in the catalytic box to generate The heat is reheated, and finally the hot water pipe returns to the hot water tank to supply hot water, which can realize water cycle heating, and the hot water in the hot water tank can be used for domestic hot water, further saving energy.

3. The utility model is equipped with a dust removal device before the boiler flue gas waste heat heating box, which can remove dust and impurities in the flue gas, and prevent dust and impurities from entering the curved flue gas heating pipe to block the pipe, thereby improving the heating of the curved flue gas. Extend the service life of the pipeline, reduce the maintenance amount and reduce the maintenance cost.

4. The utility model adopts a curved flue gas heating pipe with a curved design to increase the heating area of the flue gas, thereby improving the heating efficiency of the waste heat of the flue gas and avoiding energy waste.

5. The utility model adopts hot water circulation heating pipes, increases the area of water, further improves the heating effect of the heat generated by the catalytic reaction, and further avoids the loss of heat and the waste of energy.

6. The utility model has simple structure, relatively cheap components, low manufacturing cost, and can be widely used on a large scale.

The utility model directly uses the existing equipment and improves the existing equipment. A catalyst is arranged in the blower to make the flue gas catalyze and burn again in the blower, so that the energy can be more fully utilized and the energy utilization rate can be improved. Secondly, the hot water circulation heating pipe adopts a variable cross-section design at the corner of the pipe, which increases the heat transfer coefficient and can increase the heat transfer per unit area. At the same time, the curved pipe can perform heat transfer to the greatest extent, significantly extending the heat transfer time This enables the hot air to fully exchange heat with the cold water. In the utility model, the hot water circulation heating pipe and the curved flue gas heating pipe are all made of nickel-based alloys, such as Ni (about 70%)-Cu (about 30%) alloys. Higher than 50℃～100℃ non-gassed sulfuric acid, HF acid with a concentration of less than 50% and a temperature of less than 100℃, acetic acid and caustic alkali have good corrosion resistance and can be used in harsh conditions such as acid. heat transfer capacity. In addition, the heating system of the utility model can recycle the recovered flue gas, so that the exhaust gas can meet the discharge standard.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of an embodiment of the boiler flue gas waste heat circulation heating system of the present invention.

In the figure: 1-intake pipe, 2-blower, 3-dust removal device, 4-curved flue gas heating pipe, 5-boiler flue gas waste heat heating box, 6-outlet pipe, 7-cold water pipe, 8-catalyst addition Unit, 9-chimney, 10-drying device, 11-catalytic box, 12-hot water circulation heating pipe, 13-hot water tank, 14-indoor, 15-temperature detection and display unit, 16-hot water pipe, 17-catalysis Heating device, 18-water outlet pipe.

detailed description

The utility model will be further described in detail below in conjunction with the embodiments and accompanying drawings, but it is not used as a limitation to the protection scope of the claims of the application.

The boiler flue gas waste heat circulation heating system of the utility model (referred to as the heating system, see Fig. 1) includes an intake pipe 1, a blower 2, a dust removal device 3, a boiler flue gas waste heat heating box 5, an air outlet pipe 6, a cold water pipe 7, Chimney 9, drying device 10, hot water circulation heating pipeline 12, hot water tank 13, hot water pipeline 16, catalytic heating device 17 and water outlet pipeline 18; Described blower 2 is provided with catalyst, and the inlet end of blower 2 is connected into Gas pipeline 1, the gas outlet end is connected with one end of dust removal device 3, the boiler flue gas waste heat heating box 5 is provided with a curved flue gas heating pipe 4, one end of the curved flue gas heating pipe 4 is connected with the other end of dust removal device 3 Connection, the other end of the curved flue gas heating pipe 4 is connected with one end of the outlet pipe 6; the water inlet of the boiler flue gas waste heat heating box 5 is connected with one end of the cold water pipe 7, and the water outlet is connected with one end of the water outlet pipe 18; Catalytic heating device 17 is provided with catalytic case 11, and in catalytic heating device 17, the outer surface of catalytic case 11 is surrounded by hot water circulation heating pipeline 12; The bottom of described catalytic case 11 is connected with the other end of outlet pipe 6 , the top of the catalytic box 11 is provided with a catalyst adding unit 8; the hot water circulation heating pipeline 12 is a single-pass curved pipe, and fins are arranged on the outside of the hot water circulation heating pipeline 12, and the inside of the hot water circulation heating pipeline 12 adopts a wire mesh composite Tube core, a variable-section pipe is arranged at the turning point of the hot water circulation heating pipeline 12, one end of the hot water circulation heating pipeline 12 is connected with the other end of the outlet pipeline 18, and the other end of the hot water circulation heating pipeline 12 is connected with the hot water pipeline 16 The hot water inlet of the hot water tank 13 arranged in the indoor 14 is connected, the cold water outlet of the hot water tank 13 is connected with the other end of the cold water pipeline 7, and a temperature detection and display unit 15 is arranged inside the hot water tank 13; the drying device 10 is arranged above the catalytic heating device 17, the bottom of the drying device 10 is connected with the catalyst adding unit 8 of the catalytic heating device 17 through an exhaust pipe, and the top of the drying device is connected with the chimney 9.

The utility model is further characterized in that the intersecting surface of the inside of the variable cross-section pipe and the pipe connected at the turning is an oblique cross section of 65-75°, which can limit the flow to the greatest extent, and can also effectively prevent the variable cross-section pipe from changing due to the increase of pressure. The phenomenon of local expansion occurs at the cross section, and by changing the shape of the heat transfer surface, the flow of the fluid becomes more turbulent, destroying its boundary flow layer, and enhancing the heat transfer. The inside of the hot water circulation heating pipe 12 adopts a wire mesh composite tube core, and the inside of the wire mesh composite tube core is evenly distributed with slots, which can better control the flow rate of water, thereby increasing the heat exchange rate between water and flue gas. The heat exchange temperature difference between the curved flue gas heating pipe 4 and the hot water circulation heating pipe 12 can be controlled at about 10° C., and is not affected by seasons.

The utility model is further characterized in that the catalyst in the blower 2 is vanadium pentoxide, platinum-rhodium alloy, platinum-palladium alloy or iron-based metal. The catalyst in the catalytic case 11 is the same as the catalyst in the blower 2 .

A further feature of the present invention is that the temperature detection and display unit 15 adopts an infrared thermal sensor, which is beneficial to improve the sensitivity of temperature measurement.

A further feature of the utility model is that the dust removal device 3 adopts the DTTW-2 type flue gas dust removal device of the double alkali desulfurization technology, and the dust removal device 3 is provided with a filter screen and a drying layer inside, which can efficiently improve the dust washing efficiency; the drying device 10 There are graphite drying layer, fine filter screen and preliminary filter screen in sequence from top to bottom. Activated carbon filter uses the principle of compressor refrigeration to fully cool the high-temperature and hot and humid sample gas in the heat exchanger, so that the hot and humid gas is condensed into a liquid state, and the condensed liquid is discharged by a peristaltic pump (or other methods) to achieve gas-liquid Separation greatly reduces the water content in the measured sample gas and ensures the normal operation of related equipment.

A further feature of the present utility model is that the chimney 9 is provided with a solid particle absorbing device of a multilayer metal mesh, the metal mesh can be an aluminum foil mesh, a stainless steel mesh or a punched plate composite mesh, and the metal mesh is wavy, multi-layer The metal mesh is arranged in the chimney from top to bottom according to the pore size from thick to fine, so that the flow direction of the waste can be changed many times when the waste passes through, and its efficiency can be increased.

The working principle and usage method of the boiler flue gas residual heat circulation heating system of the utility model are as follows: the exhaust gas produced by the thermal power plant or the steel plant enters through the intake pipe 1, and is heated at the blower 2, and the blower 2 is provided with a catalyst, which can accelerate Catalytic reaction, so that the solid carbon-containing particles contained in the exhaust gas are fully burned, and the fully burned exhaust gas (here is the exhaust gas produced by ironmaking or coal burning) passes through the dust removal device 3 (DTTW-2 type using double alkali desulfurization technology) The flue gas dedusting device) enters the boiler flue gas waste heat heating box 5, and exchanges heat with the cold water in the cold water pipe 7. At this time, the temperature detection and display unit 15 in the hot water tank 13 detects the temperature in real time. When the hot water tank After the water temperature inside rises, it is indoor heating; at the same time, the fully combusted exhaust gas enters the catalytic box 11 through the outlet pipe 6 at the other end of the curved flue gas heating pipe 4 in the boiler flue gas waste heat heating box 5, and is heated again. The cold water in the water circulation heating pipeline 12 performs heat exchange, and the recirculated waste gas is discharged into the drying device 10 through the exhaust pipe, and the waste gas is cleaned of impurities, and then discharged into the air through the chimney 9 .

The utility model uses the blower 2 to introduce the flue gas generated in the thermal power plant into the dust removal device 3 for dust removal. After the dust removal, the flue gas enters the boiler flue gas waste heat heating box 5 to heat the cold water in the boiler flue gas waste heat heating box. After heating, the flue gas enters the catalytic box 11, and catalyst is added to the catalytic box 11 through the catalyst adding unit 8, and the flue gas reacts with the catalyst in the catalytic box to remove harmful gases such as sulfur dioxide and nitrogen monoxide in the flue gas , and then the flue gas after the reaction is dried by the drying device 10, and finally discharged by the chimney 9. The whole process uses the waste heat of the boiler flue gas and the heat generated by the catalytic reaction of the flue gas to heat the cold water. Energy saving, high heat exchange temperature difference, good heating effect, can also effectively remove harmful substances in the flue gas, purify the flue gas, and protect the environment; the flue gas is introduced into the boiler flue gas waste heat heating box 5 by the cold water pipe 7 for heating Heating, the heated water enters the hot water circulation heating pipe 12 in the catalytic heating device through the outlet pipe 18, uses the heat generated by the catalytic reaction in the catalytic box 11 to reheat, and finally returns to the hot water tank through the hot water pipe 16 The supply of hot water can realize water circulation heating and further save energy; a dust removal device 3 is installed before the boiler flue gas waste heat heating box 5, which can remove dust impurities in the flue gas and prevent dust impurities from entering the curved flue gas heating pipe Block the pipe, thereby improving the service life of the curved flue gas heating pipe, reducing the amount of maintenance, and reducing the maintenance cost; the flue gas heating pipe 12 adopts a curved design of one-way curved pipe, which is different according to the size of heat and fluid pressure at different sections , so that the flow rate of the water in the pipe changes, which significantly improves the heat transfer capacity of the pipe. The setting of the variable cross-section pipe at the turn can effectively prevent the heat transfer problem caused by the uneven pressure at the turn. Under the premise of ensuring the heat transfer efficiency, The cost can be significantly reduced, and the heating area of the flue gas is increased, thereby improving the heating efficiency of the waste heat of the flue gas, and effectively avoiding energy waste.

Example 1

The boiler flue gas waste heat circulation heating system in this embodiment includes an intake pipe 1, a blower 2, a dust removal device 3, a boiler flue gas waste heat heating box 5, an air outlet pipe 6, a cold water pipe 7, a chimney 9, a drying device 10, and a hot water circulation Heating pipeline 12, hot water tank 13, hot water pipeline 16, catalytic heating device 17 and water outlet pipeline 18; Described air blower 2 is provided with catalyst, and the air inlet end of air blower 2 is connected air inlet pipeline 1, and air outlet end and dedusting device 3 One end of the boiler flue gas waste heat heating box 5 is provided with a curved flue gas heating pipe 4, one end of the curved flue gas heating pipe 4 is connected to the other end of the dust removal device 3, and the curved flue gas heating pipe 4 The other end is connected to one end of the gas outlet pipeline 6; the water inlet of the boiler flue gas waste heat heating box 5 is connected to one end of the cold water pipeline 7, and the water outlet is connected to one end of the water outlet pipeline 18; the catalytic heating device 17 is provided with a catalytic box 11 , and in the catalytic heating device 17, the outer surface of the catalytic case 11 is surrounded by a hot water circulation heating pipe 12; Unit 8; the hot water circulation heating pipeline 12 is a one-way curved pipe, and fins are arranged on the outside of the hot water circulation heating pipeline 12. A variable cross-section pipe is arranged at the turning point, and one end of the hot water circulation heating pipe 12 is connected with the other end of the outlet pipe 18, and the other end of the hot water circulation heating pipe 12 is connected with the hot water tank 13 installed in the indoor 14 through the hot water pipe 16. The hot water inlet is connected, the cold water outlet of the hot water tank 13 is connected with the other end of the cold water pipeline 7, and a temperature detection and display unit 15 is arranged inside the hot water tank 13; the drying device 10 is arranged above the catalytic heating device 17, The lower part of the drying device 10 is connected to the catalyst adding unit 8 of the catalytic heating device 17 through an exhaust pipe, and the upper part of the drying device is connected to the chimney 9 .

The catalyst in the blower 2 in this embodiment is a platinum-palladium alloy catalyst, and the dust removal device 3 adopts the DTTW-2 type flue gas dust removal device of the double alkali desulfurization technology. Soot cleaning efficiency; the interior of the drying device 10 is provided with a graphite drying layer, a fine filter screen and a preliminary filter screen in turn from top to bottom, the graphite drying layer adopts porous graphite, and the fine filter screen adopts a double-layer metal mesh. The primary filter uses an activated carbon filter. The chimney 9 is provided with a multi-layer perforated plate composite net.

The tail gas recovery system of Nanjing Yire Zonglian Technology Co., Ltd. can save 30% of fuel consumption, and the recovered steam is more than ZSHH-A heat pipe waste heat recovery device (air-water) and RFHH-B heat pipe waste heat recovery device (water-gas) The average height is about 20%, while the heat exchange efficiency of the heating system in this embodiment is between 85% and 90%, and it can save more than 50% of energy, and can recycle waste heat of flue gas three times, so that in the whole process, The waste heat recovery rate reaches about 60%, which shows that the waste heat recovery of the heating system in this embodiment is comprehensive, and the energy utilization rate is high during recovery, which avoids a large waste of waste heat and can well meet the needs of industrial production, and the cost is low. Enterprises bring greater economic benefits.

The drying device, dedusting device, absorbing device, etc. involved in the utility model can all be obtained through commercial purchase.

The unmentioned parts of the utility model are applicable to the prior art.

Utilize the technical solution of the utility model, or those skilled in the art design a similar technical solution under the inspiration of the technical solution of the utility model, and achieve the above-mentioned technical effects, all fall into the protection scope of the claims of the utility model .

Claims (4)

1. a residual heat from boiler fume circulating heat supply system, it is characterised in that this heating system includes admission line, aerator, dust arrester, residual heat from boiler fume add hot tank, outlet pipe, cold water pipes, chimney, drying device, hot water circulation heated pipeline, boiler, hot water pipeline, catalytic heating device and outlet conduit；It is provided with catalyst in described aerator, the inlet end of aerator connects admission line, outlet side is connected with one end of dust arrester, described residual heat from boiler fume adds and is provided with curved flue gas pipeline in hot tank, curved one end of flue gas pipeline is connected with the other end of dust arrester, and the curved other end of flue gas pipeline is connected with one end of outlet pipe；One end of water inlet and cold water pipes that residual heat from boiler fume adds hot tank is connected, and outlet is connected with one end of outlet conduit；It is provided with catalyst container in described catalytic heating device, and in catalytic heating device, the outer surface of catalyst container is surrounded with hot water circulation heated pipeline；The bottom of described catalyst container is connected with the other end of outlet pipe, and the top of catalyst container is provided with catalyst adding device；Described hot water circulation heated pipeline is one way curve pipe, it is provided with fin outside hot water circulation heated pipeline, hot water circulation heated pipe interior adopts silk screen compound tube core, at the turning of hot water circulation heated pipeline, varying cross-section duct is set, one end of hot water circulation heated pipeline is connected with the other end of outlet conduit, the other end of hot water circulation heated pipeline is connected with the hot water inlet port of the boiler being disposed in the interior by hot water pipeline, the cooling water outlet of boiler is connected with the other end of cold water pipes, is provided with temperature detection display unit inside boiler；Described drying device is arranged on the top of catalytic heating device, and the bottom of drying device is connected with the catalyst adding device of catalytic heating device by exhaustor, and the top of drying device is connected with chimney.

2. residual heat from boiler fume circulating heat supply system according to claim 1, it is characterised in that the intersection of the pipeline that the inside of described varying cross-section duct is connected with turning is the oblique section of 65 ~ 75 °, described silk screen multiple tube core inner is evenly distributed with fluting.

3. residual heat from boiler fume circulating heat supply system according to claim 1, it is characterised in that the catalyst in described aerator is vanadic anhydride, platinum-rhodium alloy or platinum-nickel alloys catalyst.

4. residual heat from boiler fume circulating heat supply system according to claim 1, it is characterised in that described temperature detection display unit adopts infrared thermal sensor.