CN209371290U - A kind of flue gas deep treatment and waste-heat recovery device based on heat pipe heat exchanging technology - Google Patents

Abstract

The utility model relates to a kind of flue gas deep treatment and waste-heat recovery device based on heat pipe heat exchanging technology, including sequentially connected: boiler, economizer, denitrator, rotary regenerative air heater, deduster, boiler induced-draft fan, former flue, absorption tower, net flue, chimney；Rotary regenerative air heater is also connected with primary air fan, is arranged that flue gas cool-down heat exchanger, setting disappears white heat exchanger on net flue on former flue, and flue gas cool-down heat exchanger and the white heat exchanger that disappears are also connected with preheated air connecting tube；Flue gas cool-down heat exchanger and the white heat exchanger that disappears are heat exchange of heat pipes.The utility model utilizes two groups of heat-pipe heat exchangers, and the heat recovery of neat stress, former flue gas is improved the temperature of boiler First air as boiler First air to air respectively, is achieved the purpose that energy-saving.It simultaneously by air cooled neat stress temperature, reduces effectively solution chimney of electric plant and emits white cigarette phenomenon, avoid lower gypsum rain phenomenon around power plant.

Description

A flue gas advanced treatment and waste heat recovery device based on heat pipe heat exchange technology

technical field

The utility model relates to a flue gas deep treatment and waste heat recovery device based on heat pipe heat exchange technology, which is an environmental protection and energy-saving device, a device for controlling the discharge of coal-fired flue gas, and an energy-saving and emission-reducing device for coal-fired boilers. installation.

Background technique

All existing power plants are equipped with desulfurization and dust removal devices, and more than 90% of them use wet desulfurization. It is saturated wet flue gas, which contains a large amount of water vapor, and the water vapor contains more dissolved salts, SO ₃ , gel dust, fine dust, etc. (all of which are the main components of haze). If the flue gas is directly discharged from the chimney and enters the ambient air with a lower temperature, since the saturated humidity of the ambient air is relatively low, the water vapor in the flue gas will condense to form a wet plume during the temperature reduction of the flue gas. The resulting pollution of the atmosphere is not only visual but also substantial. In the past two years, the measures taken are that after the flue gas passes through the wet electrostatic precipitator to remove part of the dust, acid mist, water droplets, aerosol, odor and other harmful substances in the wet gas, it is discharged into the atmosphere through the chimney. At present, more methods are used to cool down the original flue gas, then cool down the clean flue gas first and then heat up. Specifically, the net flue gas discharged from the absorption tower is first cooled by circulating water in the condenser. The heat of the original flue gas is transferred to the net flue gas cooled by the condenser through the heat medium water to raise the temperature of the flue gas, and then discharged to the atmosphere through the chimney. Due to the large flow rate of raw flue gas and net flue gas, strong corrosion and large heat capacity, the conventional shell-and-tube heat exchanger selected is bulky and expensive. In addition, the selected process method consumes a large amount of circulating water, which puts forward high requirements for public works. If the public works cannot meet the requirements, it is necessary to design a complex circulating water cooling device. How to reduce the temperature of flue gas still needs further solution.

Contents of the invention

In order to overcome the problems of the prior art, the utility model proposes a device for advanced flue gas treatment and waste heat recovery based on heat pipe heat exchange technology. The device adopts heat pipe technology, and uses air heat exchange to lower the temperature to reduce the temperature of the exhausted flue gas, and then introduces this part of the heat exchanged heated air into the primary air, and uses the heat in it to add to the combustion process to improve the combustion efficiency.

The purpose of this utility model is achieved in this way: a flue gas deep treatment and waste heat recovery device based on heat pipe heat exchange technology, including sequentially connected: boiler, economizer, denitrifier, rotary air preheater, dust collector, Boiler induced draft fan, original flue, absorption tower, clean flue, and chimney; the rotary air preheater is also connected to a primary fan, the original flue is equipped with a flue gas cooling heat exchanger, and the clean flue is equipped with a whitening heat exchanger, the flue gas cooling heat exchanger and the whitening heat exchanger are also connected with a preheating air connecting pipe, and the preheating air connecting pipe is connected to the whitening blower, the whitening heat exchanger, the flue gas The cooling heat exchanger and the primary fan; the flue gas cooling heat exchanger and whitening heat exchanger are heat pipe heat exchangers.

Further, the heat pipe heat exchanger includes upper and lower parts, the upper part is a condensation chamber, and the lower part is an evaporation chamber. There is a heat conduction partition between the condensation chamber and the evaporation chamber, and the vertical A plurality of heat pipes are densely arranged; the condensation chamber is connected to the preheating air connecting pipe; the evaporation chamber is connected to the original flue or the clean flue.

Further, the whitening heat exchanger is provided with a condensed water collection box, and the condensed water collection box is connected to the condensed water pump and the pulping equipment in sequence.

The beneficial effects produced by the utility model are: the utility model utilizes two sets of heat pipe heat exchangers to respectively recover the heat of the clean flue gas and the original flue gas to the air as the primary air of the boiler, which increases the temperature of the primary air of the boiler to reach The purpose of saving energy and reducing consumption. At the same time, the temperature of the net flue gas cooled by air reduces the phenomenon of white smoke from the chimney of the power plant and avoids the phenomenon of gypsum rain around the power plant. The precipitated flue gas condensate can be recycled, which reduces the consumption of process water by the desulfurization device, and the reduction of the temperature of the original flue gas further reduces the consumption of process water by the absorption tower. Compared with other technologies, the utility model operates stably, and at the same time achieves the dual functions of deep control of flue gas for eliminating white smoke and energy saving and consumption reduction.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is the structural representation of the device described in Embodiment 1 of the present utility model;

Fig. 2 is a schematic structural view of the heat pipe heat exchanger according to the second embodiment of the present invention.

Detailed ways

Embodiment one:

This embodiment is a flue gas advanced treatment and waste heat recovery device based on heat pipe heat exchange technology, as shown in FIG. 1 . This embodiment includes sequentially connected: boiler 1, economizer 2, denitrifier 3, rotary air preheater 4, dust collector 5, boiler induced draft fan 6, original flue 7, absorption tower 8, clean flue 9, Chimney 10; the rotary air preheater is also connected with a primary fan 11, a flue gas cooling heat exchanger 12 is set on the original flue, a whitening heat exchanger 13 is set on the clean flue, and the flue gas cooling heat exchanger Heater and whitening heat exchanger are also connected with preheating air pipe 14, and described preheating air pipe is connected successively with whitening fan 15, whitening heat exchanger, flue gas cooling heat exchanger and primary fan; The flue gas cooling heat exchanger and whitening heat exchanger are heat pipe heat exchangers. The double solid line in Fig. 1 indicates the flow path of smoke, and the thick solid line indicates the flow path of air.

This embodiment adopts the technical route of reducing the temperature of the clean flue gas and raw flue gas and recovering the waste heat of the flue gas, aiming to achieve the purpose of energy saving and emission reduction with a new technological route. The heat exchanger used in this technical route adopts a high-efficiency heat pipe heat exchanger, which can realize high-efficiency heat exchange and save investment and operating costs.

The flue gas cooling heat exchanger and the whitening heat exchanger absorb the heat in the raw flue gas and the clean flue gas, preheat the air while reducing the temperature of the raw smoke and the clean flue gas, and then add the preheated air In the primary air, the temperature of the primary air is increased to achieve the purpose of saving energy and reducing consumption.

The preheated air is driven by the whitening blower. The air first passes through the condensation section of the whitening heat pipe heat exchanger. After absorbing the heat of the clean flue gas, the temperature of the air rises, which reduces the temperature of the clean flue gas and precipitates the condensed water of the flue gas; the temperature is preliminary The raised air then flows through the flue gas cooling heat pipe heat exchanger to further heat up the air while reducing the temperature of the original flue gas. The air recovered from the clean flue gas and raw flue gas heat is sent to the inlet of the primary fan of the boiler, and is used as combustion-supporting air for the boiler after being pressurized by the primary fan.

Use the lower temperature air driven by the whitening fan to absorb the heat in the clean flue gas, and reduce the temperature of the clean flue gas to achieve the purpose of deep flue gas treatment. The heated air is reheated by the original flue gas to further recover the original smoke The heat in the air is used, and then the preheated air is sent to the primary fan, so that the energy can be utilized in a gradient.

The temperature of the clean flue gas cooled by the air is lowered, which has a further purification effect on the clean flue gas, and can cause part of the dust, gypsum and soluble salts carried in the clean flue gas to precipitate with the condensed water, effectively solving the phenomenon of white smoke from the chimney of the power plant. Gypsum rain around the power plant is avoided, thereby reducing the concentration of pollutants emitted from the net flue gas to the atmosphere.

The condensed water of flue gas precipitated after cooling the clean flue gas can be recycled. The condensed water is made into gypsum and other products for sale through the lime powder pulping facility, and the excess water can be used for the desulfurization process, reducing the water consumption of the desulfurization process.

The reduction of raw flue gas temperature means that the load of the absorption tower is reduced, which reduces the consumption of process water by the absorption tower.

In this embodiment, an economical, efficient and reliable heat pipe heat exchanger is selected as the heat exchanger for the heat exchange between the air and the raw flue gas and the clean flue gas. Heat pipe heat exchangers are safer and more reliable than conventional shell-and-tube heat exchange equipment, and can run continuously for a long time. More importantly, the heat pipe heat exchanger has high heat exchange efficiency, small equipment size, low equipment investment, and low operating costs.

Embodiment two:

This embodiment is an improvement of the first embodiment, and is a refinement of the first embodiment on the heat pipe heat exchanger. The heat pipe heat exchanger described in this embodiment includes upper and lower parts, the upper part is a condensation chamber 16, and the lower part is an evaporation chamber 17. Between the condensation chamber and the evaporation chamber is a heat conduction partition 18, and the heat conduction partition A plurality of heat pipes 19 are densely arranged vertically, and the condensation chamber is connected to the preheating air connecting pipe; the evaporation chamber is connected to the original flue or clean flue, as shown in FIG. 2 .

This embodiment uses heat pipe technology. Heat pipes claim that heat transfer superconductors can quickly and efficiently transfer heat from the evaporation end to the condensation end.

The heat pipe heat exchanger described in this embodiment is provided with two upper and lower cavities, separated by a heat-conducting partition in the middle, and the heat pipe is installed on the heat-conducting partition. Air inlets and outlets 1601 and 1602 are provided at both ends of the condensation chamber, and flue gas inlets and outlets 1701 and 1702 are arranged at both ends of the evaporation chamber. The evaporation end of the heat pipe is arranged in the evaporation chamber, and the condensation end is arranged in the condensation chamber. A heat insulating material 1801 is provided at the installation position of the heat pipe on the heat conducting separator. These insulating materials are equivalent to separating the evaporating and condensing ends of the heat pipe.

The higher-temperature net flue gas and raw flue gas flow in the evaporation chamber, and the lower-temperature air flows in the condensation chamber, so that the heat of the higher-temperature net flue gas and raw flue gas can be conducted to the lower temperature through the heat pipe. Preheat the air in the air.

The function of the heat conduction partition is to separate the clean flue gas and the original flue gas from the air, fix the heat pipe, and separate the evaporation end and the condensation end of the heat pipe at the same time. The heat-conducting partition itself can also conduct heat, but the conduction efficiency is much lower than that of the heat pipe.

Compared with conventional heat exchange equipment, heat pipe technology has the following important features:

(1) Heat pipe heat exchangers are safer and more reliable than conventional shell-and-tube heat exchange equipment, and can run continuously for a long time. Conventional shell-and-tube heat exchange equipment generally uses a partition wall for heat exchange. The cold and hot fluids flow through both sides of the wall respectively. If there is leakage in the tube wall or the wall, it will cause production shutdown losses. The heat exchange equipment composed of heat pipes is a secondary partition heat exchange, that is, the hot fluid must pass through the evaporation section and the condensation section of the heat pipe to transfer to the cold fluid, and the heat pipe is generally impossible to be destroyed at the same time in the evaporation section and the condensation section, so Greatly enhanced the reliability of equipment operation.

(2) Fast heat transfer and high efficiency. Compared with conventional shell-and-tube heat exchangers, the heat transfer speed is hundreds of times higher and the efficiency is doubled in the case of the same heat transfer area. Therefore, the heat pipe heat exchange equipment has a smaller heat exchange area than the conventional shell-and-tube heat exchanger, and the equipment has a small overall size and flexible layout, and the investment cost is reduced by 30% to 50%.

(3) Effectively avoid the cross-flow of cold and hot fluids. Each heat pipe is a relatively independent closed unit. Both cold and hot fluids flow outside the tubes, and the cold and hot fluids are completely separated by the intermediate sealing structure.

(4) Effectively prevent dew point corrosion. By adjusting the number of heat pipes or adjusting the heat transfer area ratio of the hot and cold sides of the heat pipe, the wall temperature of the heat pipe can be raised above the dew point temperature.

(5) To effectively prevent dust accumulation, the design of the heat exchanger can adopt a variable cross-section form to ensure that the fluid flows through the heat pipe heat exchanger at an equal flow rate to achieve the purpose of self-cleaning dust.

(6) There are no rotating parts, no additional power consumption, and no need to replace components frequently. Even if some components are damaged, normal production will not be affected.

(7) The damage of a single heat pipe does not affect other heat pipes, and the impact on the overall heat exchange effect can also be ignored.

Embodiment three:

This embodiment is an improvement of the second embodiment, which is the refinement of the second embodiment regarding the heat removal of the whitening heat exchanger. The whitening heat exchanger described in this embodiment is provided with a condensed water collecting tank 20, and the condensed water collecting tank is connected to a condensed water pump 21 and a pulping equipment 22 in sequence, as shown in FIG. 1 . The thick dotted line in Figure 1 indicates the flow path of condensed water.

The clean flue gas will precipitate a large amount of condensed water in the whitening heat exchanger. The condensed water can be collected by the condensed water collection box and transported by the condensed water pump to be used for limestone powder pulping. The excess water enters the absorption tower as cooling water Spraying saves the water consumption of the desulfurization process.

Finally, it should be noted that the above is only used to illustrate the technical solution of the utility model without limitation. Although the utility model has been described in detail with reference to the preferred layout scheme, those of ordinary skill in the art should understand that the technical solutions of the utility model can be The scheme (such as the connection mode of the entire device, each connection relationship, etc.) can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present utility model.

Claims (3)

1. a kind of flue gas deep treatment and waste-heat recovery device based on heat pipe heat exchanging technology, including sequentially connected: boiler, province Coal device, denitrator, rotary regenerative air heater, deduster, boiler induced-draft fan, former flue, absorption tower, net flue, chimney；Described returns Rotatable air preheater is also connected with primary air fan, which is characterized in that flue gas cool-down heat exchanger is arranged on the former flue, on net flue The white heat exchanger that disappears is set, and the flue gas cool-down heat exchanger and the white heat exchanger that disappears are also connected with preheated air connecting tube, described Preheated air connecting tube is sequentially connected the white blower that disappears, the white heat exchanger that disappears, flue gas cool-down heat exchanger and the primary air fan；It is described Flue gas cool-down heat exchanger and the white heat exchanger that disappears be heat exchange of heat pipe.

2. the apparatus according to claim 1, which is characterized in that the heat exchange of heat pipe includes upper and lower two parts, top For condensation segment, lower part is evaporator section, is heat conduction baffle between the condensation segment and evaporator section, vertical on the heat conduction baffle More heat pipes of dense arrangement；The condensation segment is connect with preheated air connecting tube；The evaporator section and former flue or net Flue connection.

3. device according to claim 1, which is characterized in that the white heat exchanger that disappears is described equipped with condensed water collecting box Condensed water collecting box be sequentially connected condensate pump and connected with pulping equipment.