A flue gas treatment system

Abstract

The present application provides a flue gas treatment system, comprising a first absorption heat pump, a flue, the first absorption heat pump comprising a first absorber and a first condenser and a second condenser arranged in parallel, the first condenser and the second condenser being arranged inside and outside the flue respectively, a boiler water inlet pipeline sequentially passing through the first absorber and the second condenser, and a valve assembly arranged on the boiler water inlet pipeline for controlling the first absorption heat pump to recover waste heat or selectively reheat flue gas. The present application can heat the boiler water inlet pipeline by using the first absorber or the first absorber and the second condenser to recover waste heat according to needs, or when only the first absorber is used to recover waste heat, the first condenser can reheat the flue gas in the flue at this time, thereby meeting the waste heat recovery and white smoke elimination requirements of flue gas reheating under different working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flue gas treatment, in particular to a flue gas treatment system. BACKGROUND

[0002] Under the premise of limited gas, it is becoming more and more important to improve the energy efficiency of heating by using waste heat recovery technology. As for the current boiler, its technology is quite mature, and the efficiency of the boiler has reached 96%, so it is difficult to achieve better energy saving target through energy saving of the boiler equipment. Considering that the main component of the boiler fuel is fossil fuel containing a large amount of hydrogen bond, the flue gas generated by combustion contains 10-17% water vapor, and the condensation temperature of the water vapor is about 55-80℃, and the latent heat of vaporization of water vapor accounts for about 6-11% of the low heat value of the fuel. However, as for the boiler, due to the small amount of air preheating, the boiler backwater temperature and other problems, the exhaust gas temperature is generally above 60℃, so the latent heat of water vapor in the flue gas cannot be effectively utilized, and there is waste of low-temperature waste heat, and the latent heat of condensation of water vapor in the flue gas cannot be effectively utilized. At the same time, after the flue gas is discharged from the chimney, a large amount of water vapor condenses in the air to form visual "white smoke" pollution. If the water vapor in the flue gas can be condensed, the latent heat of this part of water vapor can be fully utilized, thereby maximizing the energy utilization efficiency of the boiler.

[0003] When the extreme weather, after the waste heat recovery, although the white smoke is eliminated by the waste heat recovery, due to the low air temperature and the unfavorable diffusion, a small part of the water vapor in the flue gas that has not been condensed can still form white smoke, so the discharged flue gas is reheated to raise the temperature, so that the flue gas is far away from the dew point curve, thereby avoiding the formation of white smoke near the chimney.

[0004] In order to eliminate or alleviate the white smoke phenomenon when the flue gas is discharged, heating the flue gas before it is discharged is one of the common methods for eliminating white smoke, which can keep the flue gas in a unsaturated state by reducing the relative humidity of the flue gas. However, the existing flue gas reheating devices all have certain disadvantages. For example, (1) the absorption heat pump only has the function of flue gas waste heat recovery, if high-temperature (≥120℃) steam / hot water is used as the heat source to reheat the low-temperature flue gas (about 50℃) at the outlet of the desulfurization tower, there is a problem of waste of high-grade heat energy; (2) if the gas-gas heat exchanger is used to take the high-temperature flue gas (about 150℃) after dust removal of the boiler as the heat source to reheat the low-temperature flue gas (about 50℃), it is difficult to realize the function of waste heat recovery; (3) due to the temperature of the low-temperature flue gas after the desulfurization tower being 20-50℃, if the absorption heat pump is used to simultaneously realize flue gas waste heat recovery and flue gas reheating, part of the heat energy output is used for flue gas reheating, but because the heat pump heat process is set based on flue gas waste heat recovery, the temperature of the flue gas after reheating is also not high (about 60℃-70℃), so additional reheating equipment is needed; if the intermediate water is used as the intermediate medium to heat the low-temperature flue gas at the outlet of the desulfurization tower, the heat transfer process resistance is increased, and the temperature of the flue gas after reheating is further reduced.

[0005] In view of the above, the present application is proposed. SUMMARY

[0006] The present application solves the problem that the structure of the existing flue gas treatment device is unreasonable and it is difficult to balance flue gas whitening and flue gas waste heat recovery.

[0007] To solve the above problems, the present application provides a flue gas treatment system, comprising a first absorption heat pump, a flue, the first absorption heat pump comprising a first absorber and a first condenser and a second condenser arranged in parallel, the first condenser and the second condenser being arranged inside and outside the flue respectively, a boiler water inlet pipeline sequentially passing through the first absorber and the second condenser, and a valve assembly arranged on the boiler water inlet pipeline for controlling the first absorption heat pump to selectively recover waste heat and reheat flue gas.

[0008] The arrangement can heat the boiler water inlet pipeline using the first absorber or the first absorber and the second condenser as needed to recover waste heat, or when only the first absorber is used to recover waste heat, the first condenser can reheat the flue gas in the flue at this time, thereby meeting the needs of waste heat recovery and flue gas reheat whitening under different working conditions.

[0009] Preferably, the valve assembly comprises a third valve and a fourth valve, the third valve being located between the second condenser and the first absorber, one end of the fourth valve being connected with a boiler water return pipeline, and the other end of the fourth valve being located between the outlet end of the first absorber and the third valve. This arrangement is simple in structure and convenient for production and processing. Preferably, the flue gas treatment system further comprises an electric control module, and the valve assembly is electrically connected with the electric control module.

[0010] Preferably, a first heat exchanger and a desulfurization tower are arranged in the flue, the first absorption heat pump comprises a first evaporator, the first heat exchanger is located upstream of the desulfurization tower, and the first heat exchanger is used to absorb the heat of the flue gas in the flue to heat the medium of the first evaporator.

[0011] This arrangement can take heat from the upstream position of the desulfurization tower, where the flue gas temperature is relatively high to help improve the overall operating parameters of the absorption heat pump, thereby increasing the temperature and pressure of the condenser vapor; at the same time, the condenser and the absorption heat pump are arranged separately and located downstream of the desulfurization tower, eliminating the intermediate water circuit and the corresponding heat transfer process resistance, which can heat the flue gas to 80-90℃, thereby meeting the whitening requirements of the flue gas; the working medium used by the absorption heat pump has a maximum output temperature of ≤150℃, and the heating capacity is generally 30-50℃, which can heat the boiler feed water, thereby meeting the whitening requirements of the flue gas while realizing the utilization of flue gas waste heat.

[0012] Preferably, the first absorption heat pump further comprises a first absorber and a first generator, the first absorber is coupled with the boiler water inlet pipeline to realize heat exchange, the first absorber, the first generator, the second condenser and the first evaporator are connected in sequence, and the first generator is heated by a driving heat source to generate medium steam.

[0013] The boiler backwater pipeline is heated in the absorber, and the feedwater does not enter the condenser, and part of the waste heat absorbed by the evaporator is used to heat the boiler feedwater through the circulation of the "coldant-solution" inside the absorption heat pump, thereby realizing the effect of partial waste heat recovery.

[0014] Preferably, the first absorption heat pump further comprises a second heat exchanger, the second heat exchanger is arranged in parallel with the first heat exchanger, the second heat exchanger is located on the upstream side of the first heat exchanger, and the first heat exchanger and the second heat exchanger are respectively provided with a first valve and a second valve arranged in parallel between the first heat exchanger and the second heat exchanger for switching between the first heat exchanger and the second heat exchanger.

[0015] This arrangement can ensure that the first absorption heat pump selectively takes heat from flue gas at a higher temperature, which helps to improve the overall operating parameters of the first absorption heat pump, thereby increasing the temperature and pressure of the medium steam in the first condenser.

[0016] Preferably, the first condenser is a tube bundle heat exchanger. Preferably, the inside and outside of the tube bundle are respectively supplied with medium steam and flue gas. Since the condensation of the coldant steam inside the condenser is in the form of beads, the heat transfer coefficient is much higher than that of the intermediate water, and therefore the heat transfer resistance is much smaller than that of the intermediate water, further increasing the temperature of the reheated flue gas.

[0017] Preferably, the first condenser is connected with the first generator and the first evaporator through a medium channel, a first throttling element is arranged on the medium channel, and a second throttling element is arranged between the second condenser and the first evaporator.

[0018] Preferably, the flue gas treatment system further comprises a second absorption heat pump, the second absorption heat pump comprises a second absorber, a second generator, a third condenser and a second evaporator arranged in sequence, the second generator is heated by a driving heat source to generate medium steam, the boiler water inlet pipeline is sequentially coupled with the second absorber and the third condenser to absorb heat, and the second absorption heat pump further comprises a third heat exchanger located in the flue duct for absorbing the heat of the flue gas in the flue duct to heat the medium of the second evaporator. This arrangement can balance the flue gas waste heat recovery and flue gas reheating as needed, has strong system adaptability, and has high waste heat recovery efficiency.

[0019] Preferably, a third throttling element is arranged between the third condenser and the second evaporator. The arrangement can change the pressure of the medium to play the role of throttling and pressure reduction.

[0020] Compared with the prior art, the flue gas treatment system has the following beneficial effects:

[0021] 1) The first and second absorption heat pumps are used for waste heat recovery, and when the second absorption heat pump is used for waste heat recovery and the first absorption heat pump is used for flue gas reheating, the temperature of the reheated flue gas can be increased to 80-90℃, and the waste heat recovery and flue gas whitening requirements can be met simultaneously through the absorption heat pump;

[0022] 2) The boiler feed water is heated in the absorber, and the feed water does not enter the condenser. Through the circulation of the "cold agent-solution" in the absorption heat pump, a part of the waste heat absorbed by the evaporator can be used to heat the boiler feed water, realizing the effect of partial waste heat recovery;

[0023] 3) The condenser is separated from the absorption heat pump and arranged downstream of the desulfurization tower to heat the low-temperature flue gas. The intermediate water circuit and the corresponding heat transfer process resistance are removed. When the condenser inside the cold agent vapor condenses, it is in a beaded state, and the heat transfer coefficient is much higher than that of the intermediate water. Therefore, the heat transfer resistance is much smaller than that of the intermediate water, further improving the temperature after flue gas reheating. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a whole schematic diagram of the flue gas treatment system according to embodiment 1 of the present application;

[0025] Figure 2 It is a whole schematic diagram of the flue gas treatment system according to embodiment 2 of the present application;

[0026] Figure 3 It is a whole schematic diagram of the flue gas treatment system according to embodiment 3 of the present application.

[0027] Figure 4 It is a structure schematic diagram of the cyclone device according to embodiment 3 of the present application;

[0028] Figure 5 It is a structure schematic diagram of the wind wheel assembly according to embodiment 3 of the present application.

[0029] Explanation of reference signs:

[0030] 1- first absorption heat pump; 11- first absorber; 12- first evaporator; 13- first generator; 14- first condenser; 141- medium passage; 142- first throttling element; 15- first heat exchanger; 151- first valve; 152- second valve; 16- second condenser; 161- second throttling element; 163- third valve; 164- fourth valve; 17- second heat exchanger; 2- flue; 17- second heat exchanger; 3- boiler water inlet pipeline; 4- boiler water return pipeline; 5- desulfurization tower; 6- cyclone device; 61- fan wheel assembly; 611- hub; 612- bottom plate; 613- guide ring; 614- fan blade; 6141- tooth; 6142- notch; 615- shaft sleeve; 62- support; 621- upper seat plate; 622- lower seat plate; 63- jacket; 64- air inlet plate; 7- second absorption heat pump; 71- second absorber; 72- second evaporator; 73- second generator; 74- third condenser; 741- third throttling element; 75- third heat exchanger. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings. It should be noted that the technical features in each embodiment of the present application can be combined with each other without conflict.

[0032] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection" and "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection; it can be directly connected, or indirectly connected through intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0033] In the heat loss of the boiler, the proportion of flue gas heat loss is the largest, about 6-11%, so the flue gas waste heat is also an important part of the waste heat resource. Fully recycling the waste heat resource in the flue gas not only has great economic and social benefits, but also helps to improve the efficient use of energy, which meets the development requirements of social energy saving and emission reduction. However, the existing flue gas reheating device can realize "white elimination" to a certain extent, but it cannot balance flue gas waste heat recovery and flue gas white elimination, and has the disadvantages of high cost and complex structure.

[0034] Therefore, the applicant proposes the following technical scheme:

[0035] Embodiment 1

[0036] As Figure 1As shown, a flue gas treatment system comprises a first absorption heat pump 1, a flue 2, a first heat exchanger 15 arranged in the flue 2, and a desulfurization tower 5, the first heat exchanger 15 being located upstream of the desulfurization tower 5, the first absorption heat pump 1 comprising a first evaporator 12, the first heat exchanger 15 being used to absorb heat of flue gas in the flue 2 to heat medium of the first evaporator 12, the first absorption heat pump 1 further comprising a first condenser 14, the first condenser 14 being arranged in the flue 2 and located on a downstream side of the desulfurization tower 5, and being used to reheat flue gas in the flue 2.

[0037] In the present application, the first heat exchanger 15 absorbs heat from an upstream position of the desulfurization tower 5, and the flue gas at this position has a higher temperature to help improve overall operating parameters of the first absorption heat pump 1, thereby increasing temperature and pressure of condenser vapor in the first condenser 14; meanwhile, the first condenser 14 is arranged separately from the first absorption heat pump 1 and located downstream of the desulfurization tower 5, and the intermediate water circuit and corresponding heat transfer process thermal resistance are removed, which can reheat the flue gas to 80-90℃, thereby meeting the white smoke elimination requirement of the flue gas; the working medium used by the first absorption heat pump 1 is LiBr-H2O or NH3-H2O, the maximum output temperature thereof is ≤150℃, the temperature increasing capacity is generally 30-50℃, and the first absorption heat pump 1 can heat boiler feed water, thereby realizing utilization of waste heat of the flue gas while meeting the white smoke elimination requirement of the flue gas.

[0038] Preferably, the first absorption heat pump 1 further comprises a first absorber 11 and a first generator 13, the first absorber 11 is coupled with the boiler feed water pipeline 3 and the boiler return water pipeline 4 respectively to realize heat exchange, the first absorber 11, the first generator 13, the first condenser 14, and the first evaporator 12 are connected in sequence, and the first generator 13 is heated by a driving heat source to generate medium vapor.

[0039] The boiler return water pipeline 4 is heated in the first absorber 11, and the feed water does not enter the first condenser 14, and through circulation of “condenser-solution” inside the first absorption heat pump 1, a part of waste heat absorbed by the first evaporator 12 can be used to heat the boiler feed water, thereby realizing the effect of partial waste heat recovery.

[0040] Preferably, the first condenser 14 is a tube bundle heat exchange device, and the inner and outer tubes of the tube bundle are respectively used for medium vapor and flue gas flow. Since the condensation of condenser vapor in the first condenser 14 is in the form of beads, the heat exchange coefficient is much higher than that of intermediate water, and the heat transfer thermal resistance is much smaller than that of intermediate water, thereby further increasing the temperature of the reheated flue gas.

[0041] Preferably, the first condenser 14 is connected with the first generator 13 and the first evaporator 12 through a medium channel 141, and a first throttling element 142 is arranged on the medium channel 141.

[0042] The first heat exchanger 15 absorbs heat from high-temperature (about 120-150°C) flue gas during operation and then transfers to the first evaporator 12. After that, the flue gas is desulfurized by the desulfurization tower 5 and directly heated by the first condenser 14 to increase the flue gas temperature to 80-90°C, thereby solving the problem of flue gas white smoke. For the first absorption heat pump 1, the first generator 13 generates medium steam with high temperature and pressure by driving the heat source, which enters the first condenser 14 arranged in the flue 2 through the medium passage 141, and is used for directly heating the flue gas (about 50°C) treated by the desulfurization tower 5. The medium in the first condenser 14 after heat release enters the first evaporator 12 to evaporate and continuously recycle the heat in the flue gas by the first heat exchanger 15, while the first absorber 11 absorbs the medium steam generated by the first evaporator 12, completes the “solution-coolant” cycle, heats the water in the boiler water inlet pipeline 3, and then delivers the water to the boiler through the boiler water return pipeline 4, thereby realizing waste heat recovery.

[0043] Example 2

[0044] In order to further improve the flue gas waste heat recovery and flue gas reheating functions, the applicant improves the embodiment 1 to obtain the following technical solutions:

[0045] As shown in Figure 2 The first absorption heat pump 1 further includes a second condenser 16, which is arranged in parallel with the first condenser 14 outside the flue 2. The boiler water inlet pipeline 3 sequentially passes through the first absorber 11 and the second condenser 16. A second throttling element 161 is arranged between the second condenser 16 and the first evaporator 12. A third valve 163 is arranged between the second condenser 16 and the first absorber 11. The boiler water inlet pipeline 3 is provided with a fourth valve 164. One end of the fourth valve 164 is connected with the boiler water return pipeline 4, and the other end of the fourth valve 164 is located between the outlet end of the first absorber 11 and the third valve 163.

[0046] This arrangement can heat the boiler water inlet pipeline 3 by using the first absorber 11 or the first absorber 11 and the second condenser 16 to recover waste heat as needed, or when only the first absorber 11 is used to recover waste heat, the first condenser 14 can reheat the flue gas in the flue 2 at this time, thereby meeting the needs of waste heat recovery and flue gas reheating white smoke under different working conditions.

[0047] Preferably, the first absorption heat pump 1 further comprises a second heat exchanger 17, which is arranged in parallel with the first heat exchanger 15, and is located on the upstream side of the first heat exchanger 15. The first heat exchanger 15 and the second heat exchanger 17 are respectively provided with a first valve 151 and a second valve 152, which are arranged in parallel, for switching between the first heat exchanger 15 and the second heat exchanger 17.

[0048] This arrangement can ensure that the first absorption heat pump 1 takes heat from the flue gas at a higher temperature, which helps to improve the overall operating parameters of the first absorption heat pump 1, thereby increasing the temperature and pressure of the medium vapor in the first condenser 14.

[0049] Preferably, the flue gas treatment system further comprises a second absorption heat pump 7, which comprises a second absorber 71, a second generator 73, a third condenser 74, and a second evaporator 72 arranged in series. The second generator 73 is heated by a driving heat source to generate medium vapor. The boiler water inlet pipeline 3 is sequentially coupled to the second absorber 71 and the third condenser 74 to absorb heat. The second absorption heat pump 7 further comprises a third heat exchanger 75 located in the flue 2, which is used to absorb the heat of the flue gas in the flue 2 to heat the medium of the second evaporator 72.

[0050] Preferably, a third throttling element 741 is arranged between the third condenser 74 and the second evaporator 72, which functions as throttling and pressure reduction by changing the pressure of the medium.

[0051] The different operating modes of the flue gas treatment system are described as follows:

[0052] 1) The first absorption heat pump 1 performs flue gas reheating:

[0053] After the first valve 151 is closed and the second valve 152 is opened, the flue gas in the flue 2 releases heat through the second heat exchanger 17, and the first evaporator 12 of the first absorption heat pump 1 takes heat from the flue gas at a higher temperature, which helps to improve the overall operating parameters of the first absorption heat pump 1, thereby increasing the temperature and pressure of the medium vapor in the first condenser 14. At the same time, after the fourth valve 164 is opened and the third valve 163 is closed, the boiler water inlet pipeline 3 is only heated by the first absorber 11, and the first absorption heat pump 1 is driven by the high-temperature heat source in the first generator 13. At this time, the first throttling element 142 is opened, and the second throttling element 161 is closed to balance the pressure. At this time, the medium vapor only enters the first condenser 14 and does not enter the second condenser 16. Because the intermediate water circuit and the corresponding heat transfer process resistance are removed, the achievable flue gas reheating temperature is further improved.

[0054] 2) The first absorption heat pump 1 carries out flue gas waste heat recovery:

[0055] After the first valve 151 is opened and the second valve 152 is closed, the flue gas in the flue 2 releases heat through the first heat exchanger 15, so that the first absorption heat pump 1 takes heat from the flue gas at a lower temperature; at the same time, after the fourth valve 164 is closed and the third valve 163 is opened, the boiler water inlet pipeline 3 sequentially passes through the first absorber 11 and the second condenser 16 for heating, and then enters the boiler water return pipeline 4 to complete the waste heat recovery.

[0056] The first absorption heat pump 1 is driven by the high-temperature heat source in the first generator 13, the second throttling element 161 is opened to realize pressure balance, and the first throttling element 142 is closed. The negative pressure medium vapor in the first absorption heat pump 1 only enters the second condenser 16.

[0057] 3) The second absorption heat pump 7 carries out flue gas waste heat recovery:

[0058] After the flue gas in the flue 2 releases heat through the third heat exchanger 75, the flue gas waste heat is sent to the second evaporator 72 of the second absorption heat pump 7 by the water circuit for heat release. The boiler water inlet pipeline 3 sequentially passes through the second absorber 71 and the third condenser 74 for step-by-step heating, and then enters the boiler water return pipeline 4 to complete the waste heat recovery; the second absorption heat pump 7 is driven by the high-temperature heat source in the second generator 73, and the pressure balance of the medium is realized by the third throttling element 741.

[0059] Example 3

[0060] In order to further improve the white smoke elimination effect of the flue 2, the applicant makes the following improvements on the basis of example 1 or example 2:

[0061] As shown in Figures 3-5 A flue gas treatment system, comprising a first absorption heat pump 1 and a flue 2, the flue 2 is provided with a first heat exchanger 15 and a desulfurization tower 5, the first heat exchanger 15 is located upstream of the desulfurization tower 5, the first absorption heat pump 1 comprises a first evaporator 12, the first heat exchanger 15 is used to absorb the heat of the flue gas in the flue 2 to heat the medium of the first evaporator 12, the first absorption heat pump 1 further comprises a first condenser 14, the first condenser 14 is arranged in the flue 2 and located on the downstream side of the desulfurization tower 5, and is used to reheat the flue gas in the flue 2.

[0062] The application takes heat from the upstream position of the desulfurization tower 5, where the flue gas temperature is higher to help improve the overall operating parameters of the first absorption heat pump 1, thereby increasing the temperature and pressure of the coolant vapor in the first condenser 14; meanwhile, the first condenser 14 is separately arranged from the first absorption heat pump 1 and located downstream of the desulfurization tower 5, removing the intermediate water circuit and the corresponding heat transfer process thermal resistance, which can heat the flue gas to 80-90℃, without interfering with the flow of flue gas, especially the spiral rising, while meeting the flue gas whitening and realizing the utilization of flue gas waste heat.

[0063] The cyclone device 6 is arranged in the flue 2, located between the first condenser 14 and the desulfurization tower 5, for driving the flue gas in the flue 2 to rotate. This arrangement makes the flue gas rotate upward along the side wall of the flue 2, effectively reducing the flow velocity of the flue gas in the vertical direction; compared with the traditional flue 2, the rising height of the flue gas after flowing out of the flue 2 is reduced, effectively reducing the condensation of water vapor in the flue gas with cold air at a higher position, although the temperature of the flue gas after reheating by the first condenser 14 is reduced, but the overall flue gas whitening effect is better.

[0064] Preferably, the cyclone device 6 is located at the outlet end of the flue 2, and the cyclone device 6 and the desulfurization tower 5 are respectively located on both sides of the first condenser 14. This arrangement can avoid the interference of the first condenser 14 on the rotation of the flue gas, so that the flue gas spirally rises in the flue 2.

[0065] As an example of the application, the cyclone device 6 includes a fan wheel assembly 61, which includes a hub 611, a bottom plate 612, and a guide ring 613. The lower end edge of the hub 611 extends to form the bottom plate 612, the bottom plate 612 is provided with a fan blade 614, the fan blade 614 is inserted on the bottom plate 612, the upper end of the fan blade 614 is inserted into the guide ring 613, and part of the guide ring 613 extends out of the bottom seat plate 622. When the flue gas enters from the air inlet of the guide ring 613, it finally exits from the outer circumferential side of the fan wheel assembly 61. Due to the circumferential array arrangement of the fan blades 614 along the circumferential side of the bottom plate 612, and due to the guide effect of the fan blades 614, the flue gas flow spirally rises along the side wall of the flue 2.

[0066] The projection of the hub 611 on the horizontal plane gradually increases from one end close to the bottom seat plate 622 to one side of the bottom plate 612. This arrangement can guide the flue gas entering the fan wheel assembly 61 and prevent airflow turbulence inside the fan wheel assembly 61.

[0067] The bottom plate 612, the flow guide ring 613 and the fan blade 614 form an air outlet. As a preferred example of the present application, the bottom plate 612 is provided with fan blade slots for mounting and fixing the fan blade 614; the fan blade slots are distributed equidistantly along the circumferential side of the bottom plate 612. Preferably, the two ends of the fan blade 614 are respectively connected with the bottom plate 612 and the flow guide ring 613, which makes the fan blade 614, the bottom plate 612 and the flow guide ring 613 detachable, facilitating the maintenance and assembly of the fan wheel assembly 61; of course, the fan blade 614 can also be fixed with the bottom plate 612 and the flow guide ring 613 by bonding to ensure firm assembly.

[0068] As a preferred example of the present application, the fan blade 614 is provided with a clamping tooth 6141 and a notch 6142 on the side close to the air outlet, and the notch 6142 is located below the clamping tooth 6141. This setting can stabilize the air flow at the air outlet and reduce the noise of the flue gas flow. Preferably, the top of the hub 611 is provided with a shaft sleeve 615 for rotating connection with the support 62.

[0069] As a preferred example of the present application, the cyclone device 6 comprises a support 62, the support 62 is provided with a fan wheel assembly 61, at least one end of the fan wheel assembly 61 is rotatably connected with the support 62. This setting has simple structure and is convenient for processing.

[0070] As an example of the present application, the support 62 comprises an upper seat plate 621 and a lower seat plate 622, the lower seat plate 622 is fixedly connected with the sidewall of the flue 2, the lower seat plate 622 is provided with a through air hole, the upper seat plate 621 is horizontally fixed in the flue 2 and is rotatably connected with the fan wheel assembly 61, the projection areas of the lower seat plate 622, the through air hole and the flue 2 in the horizontal direction are S1, S2 and S3 respectively, and S1 < S2 < 0.5 * S3.

[0071] This setting makes the cyclone device 6 take in air from the middle position of the lower seat plate 622, rotate through the fan wheel assembly 61 and then take out air from the circumferential side of the upper seat plate 621, so that the flue gas spirally rises in the flue 2, and at the same time, the gas pressure in the middle area of the flue 2 becomes smaller and slightly lower than the atmospheric pressure; at the same time, the cyclone device 6 can rotate under the action of the airflow, so as to balance the airflow pressure on both sides of the flue 2.

[0072] The first support rod is fixedly connected with the flue 2, and the second support rod is provided with a bearing for rotationally connecting with the wind wheel assembly 61. This arrangement can ensure that the flue gas spirally rises upward after passing through the wind wheel assembly 61, and support the two sides of the wind wheel assembly 61, thereby reducing the vibration of the wind wheel assembly 61 and further reducing the gap between the lower seat plate 622.

[0073] Preferably, the lower seat plate 622 is arranged in a circular ring or a horn shape. Preferably, the lower seat plate 622 gradually shrinks from bottom to top towards the rotation axis of the wind wheel assembly 61, and the lower seat plate 622 is provided with a wind passing hole which is consistent in size with the air inlet hole of the wind wheel assembly 61. This arrangement can guide the flue gas entering the cyclone device 6, and the flow resistance is small.

[0074] Preferably, the cyclone device 6 further comprises an upwardly inclined air inlet plate 64, and the outlet end of the air inlet plate 64 is located directly above the upper seat plate 621. This arrangement can guide and comb the rotating flue gas, and at the same time, due to the low air pressure in the middle region of the flue 2, the external air can be sucked into the flue 2 by the rotating flue gas through the air inlet plate 64, promoting the mixing of the introduced air and the flue gas to be treated, improving the uniformity of mixing or contact, and improving the controllability of the flue gas parameters to increase the white smoke elimination effect.

[0075] Preferably, the air inlet plate 64 is provided in multiple and at different heights of the flue 2, and the projection of the air inlet plate 64 on the horizontal plane is distributed in a circular array along the circle of the flue 2. This arrangement is simple in structure, and can automatically adjust the air suction ratio according to the flue gas flow and rotation speed; when the rotation speed of the flue gas is higher, the air pressure in the center of the flue 2 is lower, and at this time, the air suction ratio through the air inlet plate 64 is large, but the rising distance of the flue gas after flowing out of the flue 2 is short, and the white smoke elimination effect is good; when the rotation speed of the flue gas is lower, the air pressure in the center of the flue 2 is higher, and at this time, the air suction ratio through the air inlet plate 64 is small, thereby meeting the white smoke elimination needs of different weather conditions.

[0076] Preferably, the support 62 is provided with a driving device connected with the wind wheel assembly 61. This arrangement can control the rotation speed of the wind wheel assembly 61, thereby controlling the air introduction ratio, improving the controllability of the flue gas parameters, and improving the white smoke elimination effect.

[0077] As an example of the present application, the cyclone device 6 further comprises a jacket 63 located on the outer circumferential side of the flue 2 and arranged not lower than the wind wheel assembly 61, the inlet end of the jacket 63 is connected with the boiler water inlet pipeline 3, and the outlet end of the jacket 63 is connected with the first absorber 11. This arrangement can preheat the boiler water inlet pipeline 3 by the flue 2, and then heat the boiler water inlet pipeline 3 by the first absorber 11, so that the waste heat recovery rate is high; at the same time, the flue gas is cooled by the boiler water inlet pipeline 3, the condensed water is separated out when the cooled flue gas collides with the sidewall of the flue 2 and mixes with air during rotating upward, so that the water vapor content in the flue gas is further reduced, and the smoke whitening effect is further improved under the comprehensive action of air dilution and reheating by the first condenser 14.

[0078] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and the protection scope of the present application should be limited by the scope defined by the claims.

Claims

1. A flue gas treatment system, characterized in that, The application relates to a first absorption heat pump (1) and a flue (2), wherein the first absorption heat pump (1) comprises a first absorber (11) and a first condenser (14) and a second condenser (16) arranged in parallel, the first condenser (14) and the second condenser (16) are arranged inside and outside the flue (2) respectively, a boiler water inlet pipeline (3) passes through the first absorber (11) and the second condenser (16) in sequence, and the boiler water inlet pipeline (3) is provided with a valve assembly for controlling the first absorption heat pump (1) to perform waste heat recovery and selectively perform flue gas reheating.

2. The flue gas treatment system of claim 1, wherein, The valve assembly comprises a third valve (163) and a fourth valve (164), the third valve (163) is located between the second condenser (16) and the first absorber (11), one end of the fourth valve (164) is connected with a boiler water return pipeline (4), and the other end of the fourth valve (164) is located between the outlet end of the first absorber (11) and the third valve (163).

3. The flue gas treatment system according to claim 1 or 2, characterized in that, The flue (2) is provided with a first heat exchanger (15) and a desulfurization tower (5), the first absorption heat pump (1) comprises a first evaporator (12), the first heat exchanger (15) is located upstream of the desulfurization tower (5), and the first heat exchanger (15) is used for absorbing the heat of flue gas in the flue (2) to heat the medium of the first evaporator (12).

4. The flue gas treatment system of claim 3, wherein, The first absorption heat pump (1) further comprises a first absorber (11) and a first generator (13), the first absorber (11) is coupled with the boiler water inlet pipeline (3) to realize heat exchange, the first absorber (11), the first generator (13), the second condenser (16) and the first evaporator (12) are sequentially connected, and the first generator (13) is heated by a driving heat source to generate medium steam.

5. The flue gas treatment system of claim 4, wherein, The first absorption heat pump (1) further comprises a second heat exchanger (17), the second heat exchanger (17) is arranged in parallel with the first heat exchanger (15), the second heat exchanger (17) is located on the upstream side of the first heat exchanger (15), first and second valves (151, 152) are arranged between the first heat exchanger (15) and the second heat exchanger (17) and the first evaporator (12) respectively, and the first and second valves (151, 152) are arranged in parallel to switch between the first heat exchanger (15) and the second heat exchanger (17).

6. The flue gas treatment system of claim 5, wherein, The first condenser (14) is a tube bundle heat exchange device.

7. The flue gas treatment system of claim 6, wherein, The first condenser (14) is connected with the first generator (13) and the first evaporator (12) through a medium channel (141), a first throttling element (142) is arranged on the medium channel (141), and a second throttling element (161) is arranged between the second condenser (16) and the first evaporator (12).

8. The flue gas treatment system of claim 1, wherein, The flue gas treatment system further comprises a second absorption heat pump (7), the second absorption heat pump (7) comprises a second absorber (71), a second generator (73), a third condenser (74) and a second evaporator (72) arranged in series, the second generator (73) is heated by a driving heat source to generate medium steam, the boiler water inlet pipeline (3) is coupled with the second absorber (71) and the third condenser (74) in sequence to absorb heat, and the second absorption heat pump (7) further comprises a third heat exchanger (75) located in the flue (2) and used for absorbing heat of flue gas in the flue (2) to heat medium of the second evaporator (72).

9. The flue gas treatment system of claim 8, wherein, A third throttling element (741) is arranged between the third condenser (74) and the second evaporator (72).

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