Flue gas treatment system, method and heating system

Abstract

The present application discloses a flue gas treatment system, method, and heating system. The flue gas treatment system includes a contact heat exchange tower for receiving high-temperature flue gas and a first concentrated liquid, cooling the high-temperature flue gas through heat exchange to form a second-high-temperature flue gas, and further concentrating the first concentrated liquid to form a second concentrated liquid; a waste heat recovery heat exchanger for receiving the second-high-temperature flue gas, absorbing waste heat from the second-high-temperature flue gas through heat exchange, and forming flue gas condensate; an evaporator for receiving the flue gas condensate, heating and evaporating it to form steam and a first concentrated liquid, and feeding the first concentrated liquid into the contact heat exchange tower; and a condenser for receiving the steam and condensing it to form condenser condensate. The present application utilizes high-temperature flue gas for wastewater purification while cooling and purifying the high-temperature flue gas itself, thereby reducing the cost of wastewater purification and preventing the high-temperature flue gas from being directly discharged into the atmosphere and causing negative environmental impacts.

Description

Technical Field

[0001] The present application relates to the fields of environmental protection and heating technology, and in particular to a flue gas treatment system, method and heating system. Background Art

[0002] With the rapid development of the economy and society and the continuous advancement of urbanization, environmental protection and water resource shortage have become two important factors restricting the sustainable development of social economy.

[0003] Especially in the field of heating, the direct emission of high-temperature flue gas will have a great negative impact on environmental protection, and the reuse of wastewater is also an important part of achieving efficient use of water resources in the heating system.

[0004] However, the cost of wastewater purification in existing technologies is generally high, which greatly affects the purification and reuse of wastewater, and there is also a lack of effective means for the purification and utilization of high-temperature flue gas. Summary of the Invention

[0005] (1) Purpose of the invention

[0006] The purpose of this application is to provide a flue gas treatment system while providing heat, so that the high-temperature flue gas itself can be cooled and purified while being used to purify wastewater.

[0007] (2) Technical solution

[0008] In the first aspect, an embodiment of the present application provides a flue gas treatment system, including a contact heat exchange tower, a waste heat recovery heat exchanger, an evaporator and a condenser; the contact heat exchange tower receives high-temperature flue gas and a first concentrated liquid through the heat exchange tower flue gas inlet and the heat exchange tower concentrated liquid inlet, respectively, and forms sub-high-temperature flue gas and a second concentrated liquid through heat exchange; the waste heat recovery heat exchanger receives the sub-high-temperature flue gas and hot water through the heat exchanger flue gas inlet and the heat exchanger water inlet, respectively, and forms flue gas condensate and low-temperature flue gas directly discharged into the atmosphere through heat exchange; the evaporator receives the flue gas condensate and high-temperature hot water through the evaporator first water inlet and the evaporator second water inlet, respectively, and forms steam and the first concentrated liquid through evaporation; the condenser receives the steam and low-temperature hot water through the condenser steam inlet and the condenser water inlet, respectively, and forms condenser condensate through heat exchange.

[0009] In a second aspect, an embodiment of the present application provides a heating system, comprising:

[0010] A heat source, the high-temperature flue gas outlet of the heat source is connected to the flue gas inlet of the contact heat exchange tower of the flue gas treatment system of the first aspect, the water inlet of the heat source is connected to the condenser water outlet of the condenser of the flue gas treatment system of the first aspect, and the water outlet of the heat source is connected to the evaporator water inlet of the evaporator of the flue gas treatment system of the first aspect.

[0011] The heat network, the water supply port of the heat network is connected to the second water outlet of the evaporator of the evaporator of the flue gas treatment system of the first aspect, and the return water port of the heat network is connected to the condenser water inlet of the condenser of the flue gas treatment system of the first aspect.

[0012] In a third aspect, an embodiment of the present application provides a flue gas treatment method, comprising:

[0013] receiving high-temperature flue gas and a first concentrated liquid through a contact heat exchange tower, causing the high-temperature flue gas to absorb part of the water in the first concentrated liquid through heat exchange, cooling it to form a second-high-temperature flue gas, and causing the first concentrated liquid to lose water to form a second concentrated liquid;

[0014] The waste heat recovery heat exchanger receives the sub-high temperature flue gas, absorbs the waste heat in the sub-high temperature flue gas through heat exchange, and forms low temperature flue gas and flue gas condensate with a lowered temperature;

[0015] receiving the flue gas condensate through an evaporator, forming steam and a first concentrated liquid through evaporation, and sending the first concentrated liquid into the contact heat exchange tower;

[0016] The steam is received by a condenser and condensed to form condensate.

[0017] A flue gas treatment system in an embodiment of the present application is provided with a contact heat exchange tower, a waste heat recovery heat exchanger, an evaporator and a condenser in the system. The high-temperature flue gas is received by the contact heat exchange tower, and the sub-high-temperature flue gas after cooling is discharged. The waste heat of the sub-high-temperature flue gas is then absorbed by the waste heat recovery heat exchanger to form low-temperature flue gas, which is then discharged into the atmosphere and flue gas condensate is formed at the same time. The flue gas condensate is evaporated by the evaporator to form steam and a first concentrated liquid. Finally, the steam is sent to the condenser for condensation to form condensate output.

[0018] (3) Beneficial effects

[0019] The beneficial effect of the technical solution of the present application is that while high-temperature flue gas is used to purify wastewater, the high-temperature flue gas itself is cooled and purified, which reduces the cost of wastewater purification and avoids the high-temperature flue gas being directly discharged into the atmosphere, causing negative impacts on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a schematic diagram of the system structure of an embodiment of the flue gas treatment system of the present application;

[0021] Figure 2 yes Figure 1 Schematic diagram of the improved system structure of the embodiment;

[0022] Figure 3 This is a schematic diagram of the system structure of another embodiment of the flue gas treatment system of the present application;

[0023] Figure 4 yes Figure 3 Schematic diagram of the improved system structure of the embodiment;

[0024] Figure 5 yes Figure 3 A schematic diagram of the system structure of another improved embodiment;

[0025] Figure 6 yes Figure 3 A schematic diagram of the system structure of another improved embodiment;

[0026] Figure 7 yes Figure 3 A schematic diagram of the system structure of another improved embodiment;

[0027] Figure 8 This is a system structure diagram of the heating system of this application;

[0028] Figure 9 yes Figure 8 A block diagram of the improved system structure of the embodiment;

[0029] Figure 10 yes Figure 8 A block diagram of a system structure of another improved embodiment;

[0030] Figure 11 It is a flow chart of the flue gas treatment method of the present application.

[0031] Reference numerals:

[0032] 10: Condenser; 11: Condenser water inlet; 12: Condenser water outlet; 13: Condenser steam inlet; 14: Condenser condensate outlet; 15: Condenser second water inlet

[0033] 100: heat exchanger; 101: first water inlet of heat exchanger; 102: first water outlet of heat exchanger; 103: second water inlet of heat exchanger; 104: second water outlet of heat exchanger.

[0034] 20: evaporator; 21: first water inlet of evaporator; 22: first water outlet of evaporator; 23: second water inlet of evaporator; 24: second water outlet of evaporator; 25: steam outlet of evaporator.

[0035] 30: Contact heat exchange tower; 31: Flue gas inlet of heat exchange tower; 32: Flue gas outlet of heat exchange tower; 33: Concentrate inlet of heat exchange tower; 34: Concentrate outlet of heat exchange tower.

[0036] 40: Waste heat recovery heat exchanger; 41: Heat exchanger water inlet; 42: Heat exchanger water outlet; 43: Heat exchanger flue gas inlet; 44: Heat exchanger flue gas outlet; 45: Flue gas condensate water outlet.

[0037] 50: solid-liquid separation device; 51: concentrated liquid inlet; 52: solid matter outlet; 53: separated liquid outlet.

[0038] 60: Flash tank; 61: Flash tank water inlet; 62: Flash tank steam outlet; 63: Flash tank water outlet.

[0039] 600: heater; 601: heater water inlet; 602: heater steam inlet; 603: heater water outlet.

[0040] 70: heat source; 71: high-temperature flue gas outlet; 72: heat source water inlet; 73: heat source water outlet, 74: low-temperature water inlet; 75: low-temperature water outlet.

[0041] 80: Heating network; 81: Heating network water supply inlet; 82: Heating network return inlet. DETAILED DESCRIPTION

[0042] The embodiments of the present application relate to the intersecting technical field of wastewater treatment and heat supply. In some embodiments, the flue gas treatment system provided by the present application can first absorb the heat of high-temperature flue gas through a contact heat exchange tower for wastewater treatment, and then use the waste heat recovery heat exchanger to absorb the waste heat of the flue gas containing wastewater that evaporates into steam for heating, and form flue gas condensate, and then evaporate the flue gas condensate through an evaporator to obtain steam and a first concentrated liquid, and then input the steam into a condenser to form condensate output as a reusable water resource, and input the first concentrated liquid into a contact heat exchange tower for further concentration to obtain a second concentrated liquid, and then input the second concentrated liquid into a solid-liquid separation device for solid-liquid separation, and discharge the solid matter and the separated liquid respectively. The discharged separated liquid can also be input into the contact heat exchange tower as the first concentrated liquid for further circulation treatment, and the discharged solid matter can be used as industrial salt.

[0043] To make the objectives, technical solutions, and advantages of this application more clearly understood, this application is further described below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely illustrative and are not intended to limit the scope of this application. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion in the concepts of this application.

[0044] Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0045] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0046] Figure 1 It is a schematic diagram of the system structure of an embodiment of the flue gas treatment system of the present application.

[0047] like Figure 1 As shown, a flue gas treatment system includes a contact heat exchange tower 30, a waste heat recovery heat exchanger 40, an evaporator 20 and a condenser 10; the contact heat exchange tower 30 receives high-temperature flue gas and a first concentrated liquid through a heat exchange tower flue gas inlet 31 and a heat exchange tower concentrated liquid inlet 33, respectively, and forms a sub-high-temperature flue gas and a second concentrated liquid through heat exchange; the waste heat recovery heat exchanger 40 receives the sub-high-temperature flue gas and heated water through a heat exchanger flue gas inlet 44 and a heat exchanger water inlet 41, respectively, and forms flue gas condensed water and a direct discharge Low-temperature flue gas from the atmosphere; the evaporator 20 receives the flue gas condensate and high-temperature hot water respectively through the evaporator first water inlet 21 and the evaporator second water inlet 23, and forms steam and the first concentrated liquid through evaporation; the condenser 11 receives the steam through the condenser steam inlet 13, receives the low-temperature hot water through the condenser water inlet 11, discharges the low-temperature hot water with a temperature increased after heat exchange through the condenser water outlet 12, and discharges the condenser condensate formed by the steam through the condenser condensate outlet 14.

[0048] To better understand the correspondence between the inputs and outputs of each component in the flue gas treatment system, please refer to the following table:

[0049]

[0050] In this embodiment, while high-temperature flue gas is used to purify wastewater, the high-temperature flue gas itself is cooled and purified. On the one hand, the cost of wastewater purification is reduced by using high-temperature flue gas, and on the other hand, the negative impact of high-temperature flue gas directly discharged into the atmosphere on the environment is avoided.

[0051] In some embodiments, such as Figure 1As shown, the condenser 10 includes a condenser steam inlet 13, which is connected to the evaporator steam outlet 25 of the evaporator 20 and is used to receive the steam discharged from the evaporator 20; a condenser condensate outlet 14, which is used to discharge the condenser condensate formed after the steam is condensed from the condenser; a condenser water inlet 11, which is used to receive low-temperature hot water from outside the system; and a condenser water outlet 12, which is used to discharge the low-temperature hot water whose temperature has increased after absorbing heat from the condenser.

[0052] In some embodiments, when the flue gas treatment system is connected to a heating system, the low-temperature hot water received from outside the system can be return water from the heating network. Condensate discharged from the condenser 10 can also be added to the heating system as a water source. It should be understood that low-temperature hot water is a relative term, and the inventive concept of the embodiments of this application is not limited to a specific temperature range of hot water.

[0053] In some embodiments, such as Figure 1 As shown, the evaporator 20 includes a first water inlet 21 of the evaporator, which is connected to the flue gas condensate outlet 45 of the waste heat recovery heat exchanger 40, and is used to receive the flue gas condensate formed in the waste heat recovery heat exchanger 40; the first water outlet 22 of the evaporator is used to output the first concentrated liquid formed after the flue gas condensate is evaporated; the steam outlet 25 is used to output the steam formed after the flue gas condensate is evaporated; the second water inlet 23 of the evaporator is used to receive high-temperature hot water from outside the system; the second water outlet 24 of the evaporator is used to discharge the high-temperature hot water whose temperature is reduced after heat exchange from the evaporator.

[0054] Among them, the high-temperature hot water from outside the system, in some embodiments, when the flue gas treatment system is connected to the heating system, the high-temperature hot water can be hot water supplied from a heat source, and the second water outlet 24 of the evaporator will supply the high-temperature hot water with a lower temperature after heat exchange to the heating network.

[0055] In some embodiments, such as Figure 1 As shown, the contact heat exchange tower 30 includes a heat exchange tower flue gas inlet 31 for receiving high-temperature flue gas from outside the system; a heat exchange tower flue gas outlet 32 ​​for discharging sub-high-temperature flue gas formed after heat exchange and cooling from the contact heat exchange tower; a heat exchange tower concentrate inlet 33, which is connected to the evaporator first water outlet 22 of the evaporator 20 and is used to receive the first concentrate output by the evaporator first water outlet 22; and a heat exchange tower concentrate outlet 34 for outputting a second concentrate formed by the first concentrate losing water after heat exchange.

[0056] The heat exchange tower flue gas inlet 31 receives high-temperature flue gas from outside the system, and the heat exchange tower flue gas outlet 32 ​​outputs the sub-high-temperature flue gas formed after heat exchange and cooling to the flue gas inlet 43 of the waste heat recovery heat exchanger 40. The heat exchange tower concentrate inlet 33 is connected to the evaporator first water outlet 22 of the evaporator 20, receiving the first concentrate from the evaporator 20. The heat exchange tower concentrate outlet 34 outputs the second concentrate obtained by further concentration in the contact heat exchange tower. In some embodiments, when the flue gas treatment system is connected to a heating system, the high-temperature flue gas from outside the system is high-temperature flue gas discharged from a heat source, such as a boiler or heat pump. The high-temperature flue gas in the contact heat exchange tower 30 exchanges heat with the first concentrated liquid in a contact heat exchange manner. That is, the first concentrated liquid is directly released in the contact heat exchange tower 30 in a spraying manner to cool the high-temperature flue gas. At the same time, the first concentrated liquid is further concentrated to obtain a second concentrated liquid. The water evaporated from the first concentrated liquid is discharged from the heat exchange tower flue gas outlet 32 ​​along with the lower-temperature flue gas.

[0057] In some embodiments, such as Figure 1 As shown, the waste heat recovery heat exchanger 40 includes a heat exchanger water inlet 41 for receiving hot water from outside the system; a heat exchanger water outlet 42 for discharging the hot water whose temperature has increased after heat exchange; a heat exchanger flue gas inlet 43, which is connected to the heat exchange tower flue gas outlet 32 ​​of the contact heat exchange tower 30, and is used to receive the sub-high temperature flue gas discharged from the heat exchange tower flue gas outlet 32; a heat exchanger flue gas outlet 44, which is used to discharge low-temperature flue gas, and the low-temperature flue gas is the flue gas formed after the sub-high temperature flue gas is cooled; a flue gas condensate outlet 45, which is connected to the first water inlet 21 of the evaporator of the evaporator, and is used to output the flue gas condensate formed during the cooling process of the sub-high temperature flue gas.

[0058] The heat exchanger water inlet 41 is connected to a water source external to the system. In some embodiments, when the flue gas treatment system is connected to a heating system, the external water source can be return water from a tap water network. The heat exchanger water outlet 42 can output the heated water after heat exchange to the heat source as water supply for the heat source. The heat exchanger flue gas inlet 43 is connected to the flue gas outlet 32 ​​of the contact heat exchange tower 30, receiving the sub-high-temperature flue gas from the contact heat exchange tower 30. The sub-high-temperature flue gas absorbs waste heat from the hot water in the waste heat recovery heat exchanger 40, forming low-temperature flue gas and flue gas condensate. The low-temperature flue gas is discharged through the heat exchanger flue gas outlet 44, and the flue gas condensate is transported to the first evaporator water inlet 21 of the evaporator 20 via the flue gas condensate outlet 45. The heat exchange method in the waste heat recovery heat exchanger 40 can be contact heat exchange or partition heat exchange. Taking the partition-type heat exchange method as an example, after the sub-high temperature flue gas enters the waste heat recovery heat exchanger 40, the hot water will absorb the waste heat of the sub-high temperature flue gas through the partition-type heat exchange method, that is, without direct contact, so that the sub-high temperature flue gas is converted into low-temperature flue gas with a lower temperature and then directly discharged into the atmosphere from the heat exchanger flue gas outlet 44. At the same time, in the process of cooling the sub-high temperature flue gas, the moisture carried in the flue gas is released to form flue gas condensate.

[0059] Figure 2 yes Figure 1 Schematic diagram of the improved system structure of the embodiment.

[0060] In some embodiments, such as Figure 2 As shown, the contact heat exchange tower 30 includes a heat exchange tower concentrated liquid outlet 34, and the flue gas treatment system also includes a solid-liquid separation device 50, and the concentrated liquid inlet 51 of the solid-liquid separation device is connected to the heat exchange tower concentrated liquid outlet 34 for receiving the second concentrated liquid.

[0061] In some embodiments, such as Figure 2 As shown, the solid-liquid separation device 50 includes a solid outlet 52 for discharging the separated solids and a separation liquid outlet 53 for discharging the separated separation liquid.

[0062] In this embodiment, the solid-liquid separation device 50 is added to further process the second concentrated liquid discharged from the contact heat exchange tower 30 to achieve better protection of the environment.

[0063] Figure 3 This is a schematic diagram of the system structure of another embodiment of the flue gas treatment system of the present application.

[0064] In some embodiments, such as Figure 3As shown, the waste heat recovery heat exchanger 40 includes a flue gas condensate water outlet 45, the evaporator 20 is a multi-stage evaporator, and each stage of the multi-stage evaporator includes an evaporator first water inlet 21 and an evaporator first water outlet 22. The evaporator first water inlet 21 is connected in parallel to the flue gas condensate water outlet 45, and the evaporator first water outlet 22 is connected in parallel to the heat exchange tower concentrate inlet 33.

[0065] In some embodiments, such as Figure 3 As shown, each stage of the multi-stage evaporator includes a first water inlet 21 of the evaporator, a second water inlet 23 of the evaporator, a first water outlet 22 of the evaporator, a second water outlet 24 of the evaporator, and an evaporator steam outlet 25; starting from the second stage of the multi-stage evaporator, the second water inlet 23 of each stage of the evaporator is converted into an evaporator steam inlet 23, and the second water outlet 24 of the evaporator is converted into an evaporator condensate outlet 24, and starting from the second stage, the evaporator steam inlet 23 of each stage of the evaporator is connected to the evaporator steam outlet 25 of the previous stage of the evaporator.

[0066] In some embodiments, such as Figure 3 As shown, taking a three-stage evaporator as an example, each of the first, second, and third-stage evaporators includes a first evaporator water inlet 21, a first evaporator water outlet 22, a second evaporator water inlet 23, a second evaporator water outlet 24, and an evaporator steam outlet 25. The second evaporator water inlet 23 in the first stage serves as a water inlet, receiving high-temperature hot water from outside the system. The second evaporator water outlet 24 is used to discharge the high-temperature hot water after heat exchange and cooling. The second evaporator water inlet 23 in the second and third stages is converted into an evaporator steam inlet 23, receiving steam discharged from the evaporator steam outlet 25 of the previous stage. The second evaporator water outlet 24 in the second and third stages is converted into an evaporator condensate outlet 24, discharging condensate formed after heat exchange in the current stage evaporator with steam from the previous stage. The third-stage evaporator steam outlet 25 is connected to the condenser steam inlet 13 of the condenser 10, allowing the steam formed in each stage of the evaporator 20 to be fed into the condenser 10 for final condensation. In some embodiments, if the multi-stage evaporator has 4, 5, 6, or even 10 or more stages, the first and last stages have the same configuration as the first and last stages of the aforementioned three-stage evaporator, and the intermediate stages have the same configuration as the second stage of the aforementioned three-stage evaporator. If the evaporator has two stages, the first and second stages have the same configuration as the first and last stages of the aforementioned three-stage evaporator, respectively. The inventive concept of this application is not limited to the specific number of stages.

[0067] Figure 4 yes Figure 3 Schematic diagram of the improved system structure of the embodiment.

[0068] In some embodiments, such as Figure 4 As shown, the multi-stage evaporator starts from the second-stage evaporator and does not include the last-stage evaporator. The evaporator condensate outlet of each stage evaporator is connected to a flash tank 60, and the flash tank water inlet 61 of the flash tank 60 is connected to the evaporator condensate outlet 24 of the evaporator 20 of this stage; the flash tank steam outlet 62 of the flash tank 60 is connected to the evaporator steam inlet 23 of the next stage evaporator.

[0069] The flash tank 60 includes a flash tank water inlet 61, which is connected to the second water outlet 24 of the evaporator at this stage and is used to receive the evaporator condensate formed in the evaporator 20 at this stage; a flash tank steam outlet 62, which is connected to the second water inlet 23 of the evaporator at the next stage and is used to output the flashed steam to the evaporator at the next stage; and a flash tank water outlet 63, which is used to discharge the evaporator condensate whose temperature has been reduced after flash evaporation.

[0070] In some embodiments, the flash tank water outlet 63 of the previous flash tank 60 is connected to the flash tank water inlet 61 of the next flash tank 60, and the water in each stage of the flash tank 60 is output from front to back.

[0071] In some embodiments, the flash tank water outlet 63 of the previous flash tank 60 is connected in parallel with the condensate outlet 24 of the next evaporator 20, and the evaporator condensate with reduced temperature output by the previous flash tank 60 and the evaporator condensate output by the next evaporator 20 enter the next flash tank 60 together.

[0072] In some embodiments, such as Figure 4Taking a three-stage evaporator as an example, the first, second, and third-stage evaporators each include a second evaporator water inlet 23, a second evaporator water outlet 24, a first evaporator water inlet 21, a first evaporator water outlet 22, and a steam outlet 25. The second evaporator water inlet 23 in the first-stage evaporator 20 serves as a water inlet, receiving high-temperature hot water from outside the system. The second evaporator water outlet 24 is used to discharge the high-temperature hot water after heat exchange and cooling. The second evaporator water inlet 23 in the second and third-stage evaporators serves as a steam inlet, receiving steam discharged from the steam outlet 25 of the previous evaporator. The second evaporator water outlet 24 in the second and third-stage evaporators outputs condensed water converted from steam in the corresponding evaporator. The second evaporator water outlet 24 of the second-stage evaporator is connected to the flash tank water inlet 61 of the flash tank 60, for transporting the evaporator condensate formed in the second-stage evaporator to the flash tank 60. The flash tank 60 flashes the evaporator condensate to form steam, which is then transported to the second evaporator water inlet 23 of the third-stage evaporator through the flash tank steam outlet 62. The evaporator condensate, whose temperature has further decreased after flash evaporation, is then discharged through the flash tank water outlet 63. In some embodiments, if the multi-stage evaporator has 4, 5, 6, or even 10 or more stages, the first and last stages have the same configuration as the first and last stages of the aforementioned three-stage evaporator, and the intermediate stages have the same configuration as the second stage of the aforementioned three-stage evaporator. If the evaporator has two stages, the first and second stages have the same configuration as the first and last stages of the aforementioned three-stage evaporator, respectively. The inventive concept of this application is not limited to the specific number of stages.

[0073] Figure 5 yes Figure 3 A schematic diagram of the system structure of another improved embodiment.

[0074] In some embodiments, such as Figure 5 As shown, the multi-stage evaporator starts from the second-stage evaporator, and the steam outlet of each stage evaporator is connected to a heater 600, and the heater water inlet 601 of the heater 600 is connected to the evaporator condensate outlet 24 of the next stage evaporator; the heater steam inlet 602 of the heater 600 is connected to the evaporator steam outlet 25 of the evaporator 20 of this stage.

[0075] The heater 600 includes a heater water inlet 601, which is connected to the second water outlet 24 of the evaporator of the next stage evaporator, and is used to receive the evaporator condensate formed in the next stage evaporator 20; a heater steam inlet 602, which is connected to the steam outlet 25 of this evaporator, and is used to receive the steam discharged from the evaporator 20 of this stage; and a heater water outlet 603, which is used to output the evaporator condensate that has absorbed the heat of the steam.

[0076] In some embodiments, such as Figure 5As shown, the condenser condensate outlet 14 of the condenser 10 is connected to the heater water inlet 601 of the last stage heater 600 , and the condenser condensate of the condenser 10 merges with the evaporator condensate of the last stage evaporator and enters the last stage heater 600 .

[0077] In some embodiments, such as Figure 5 As shown, the heater water outlet 603 of the rear heater 600 is connected to the heater water inlet 601 of the front heater 600, and is used to output the hot water formed in each stage of the heater 600 from the rear to the front.

[0078] Figure 6 yes Figure 3 A schematic diagram of the system structure of another improved embodiment.

[0079] In some embodiments, such as Figure 6 As shown, the flue gas treatment system also includes a heat exchanger 100, the first water inlet 101 of the heat exchanger of the heat exchanger is connected to the condenser condensate outlet 14 of the condenser, for receiving the condenser condensate; the first water outlet 102 of the heat exchanger of the heat exchanger is used to discharge the condenser condensate whose temperature is reduced after heat exchange; the second water inlet 103 of the heat exchanger 100 is connected to the flue gas condensate outlet 45 of the waste heat recovery heat exchanger 40, for receiving the flue gas condensate; the second water outlet 104 of the heat exchanger 100 is connected to the evaporator first inlet 21 of the evaporator, for outputting the flue gas condensate whose temperature is increased after heat exchange to the evaporator 20.

[0080] The heat exchanger 100 includes a first water inlet 101 of the heat exchanger, which is connected to the condenser condensate outlet 14 of the condenser 10 and is used to receive the condenser condensate of the condenser 10; a first water outlet 102 of the heat exchanger, which is used to discharge the condenser condensate whose temperature is reduced after heat exchange; a second water inlet 103 of the heat exchanger, which is connected to the flue gas condensate outlet 45 of the waste heat recovery heat exchanger 40, and is used to receive the flue gas condensate formed in the waste heat recovery heat exchanger 40; and a second water outlet 104 of the heat exchanger, which is connected to the evaporator first water inlet 21 of the evaporator 20, and is used to send the flue gas condensate whose temperature is increased after heat exchange into the evaporator 20.

[0081] In this embodiment, the heat exchanger 100 is provided to further extract the waste heat of the condenser condensate output from the condenser 10, and to use the waste heat to preheat the flue gas condensate entering the evaporator 20, so that the flue gas condensate can be more effectively evaporated after entering the evaporator 20.

[0082] In some embodiments, such as Figure 6As shown, the low-temperature hot water from outside the system received by the condenser 10 and the hot water from outside the system received by the waste heat recovery heat exchanger 40 are from the same water source. When the flue gas treatment system is connected to the heating system, the same water source is generally the return water of the heating network.

[0083] Figure 7 yes Figure 3 A schematic diagram of the system structure of another improved embodiment.

[0084] In some embodiments, such as Figure 7 As shown, the condenser 10 also includes a second water inlet 15 of the condenser, which is connected to the evaporator condensate outlet 24 of at least one stage evaporator in the multi-stage evaporator, and is used to receive the evaporator condensate discharged from the multi-stage evaporator. The heat of the evaporator condensate is released through heat exchange in the condenser and then discharged from the condenser condensate outlet 14 of the condenser.

[0085] The purpose of adding a second water inlet 15 to the condenser 10 is that the evaporator condensate coming out of the evaporator usually has a relatively high temperature. In order not to waste the heat in the evaporator condensate, it can be input into the condenser 10 together with the steam output from the steam outlet 25 of the evaporator 20.

[0086] In some embodiments, such as Figure 7 As shown, each stage of the multi-stage evaporator includes an evaporator first water inlet 21 and an evaporator first water outlet 22. The evaporator first water outlet 22 of the previous stage evaporator in the multi-stage evaporator is cascaded with the evaporator first water inlet 21 of the next stage evaporator, wherein the evaporator first water inlet 21 of the first stage evaporator is connected to the flue gas condensate outlet 45 of the waste heat recovery heat exchanger 40, and the evaporator first water outlet 22 of the last stage evaporator is connected to the heat exchange tower concentrate inlet 33 of the contact heat exchange tower 30.

[0087] In this embodiment, the first water inlet of the evaporator is only set at the first stage, and the flue gas condensate is gradually concentrated in each stage, and finally a first concentrated liquid with a higher degree of concentration is formed, so that the second concentrated liquid generated subsequently and output to the solid-liquid separation device 50 is easier to handle during solid-liquid separation.

[0088] In some embodiments, such as Figure 7As shown, taking a three-stage evaporator as an example, the first, second, and third-stage evaporators each include a second evaporator water inlet 23, a second evaporator water outlet 24, a first evaporator water inlet 21, a first evaporator water outlet 22, and a steam outlet 25. The second evaporator water inlet 23 in the first-stage evaporator 20 serves as a water inlet, receiving high-temperature hot water from outside the system. The second evaporator water outlet 24 is used to discharge the high-temperature hot water after heat exchange and cooling. The second evaporator water inlets 23 in the second and third-stage evaporators serve as steam inlets, receiving steam discharged from the steam outlet 25 of the previous evaporator. The second evaporator water outlets 24 in the second and third-stage evaporators output condensed water from the steam generated in the respective evaporators. The first evaporator water inlet 21 of the second-stage evaporator communicates with the first evaporator water outlet 22 of the first-stage evaporator to receive the condensate formed in the first-stage evaporator. The first evaporator water inlet 21 of the third-stage evaporator communicates with the first evaporator water outlet 22 of the second-stage evaporator to receive the condensate formed in the second-stage evaporator. The condensate outlet of the third stage, serving as the final outlet for the condensate from the multi-stage evaporator, is connected to the condensate inlet 33 of the heat exchange tower 30, for ultimately delivering the condensate formed by the multi-stage evaporator to the heat exchange tower 30. In some embodiments, if the multi-stage evaporator has 4, 5, 6, or even 10 or more stages, the first and last stages have the same configuration as the first and last stages of the aforementioned three-stage evaporator, and the intermediate stages have the same configuration as the second stage of the aforementioned three-stage evaporator. If the evaporator has two stages, the first and second stages have the same configuration as the first and last stages of the aforementioned three-stage evaporator, respectively. The inventive concept of this application is not limited to the specific number of stages.

[0089] Figure 8 It is a system structure block diagram of the heating system of this application.

[0090] like Figure 8 As shown, a heating system includes:

[0091] The heat source 70, the high-temperature flue gas outlet 71 of the heat source is connected to the flue gas inlet 31 of the contact heat exchange tower 30 of the flue gas treatment system, the water inlet 72 of the heat source is connected to the condenser water outlet 12 of the condenser 10 of the flue gas treatment system, and the water outlet 73 of the heat source 70 is connected to the evaporator second water inlet 23 of the evaporator 20 of the flue gas treatment system.

[0092] The heat network 80, the water supply port 81 of the heat network 80 is connected to the evaporator second water outlet 24 of the evaporator 20 of the flue gas treatment system, and the return water port 82 of the heat network 80 is connected to the condenser water inlet 11 of the condenser 10 of the flue gas treatment system.

[0093] Figure 9 yes Figure 8 A block diagram of the improved system structure of the embodiment.

[0094] In some embodiments, such as Figure 10 As shown, the waste heat recovery heat exchanger 40 of the flue gas treatment system is also passed between the return water port 82 of the heat network 80 and the condenser water inlet 14 of the condenser 10 of the flue gas treatment system. The return water port 82 is connected to the heat exchanger water inlet 41 of the waste heat recovery heat exchanger 40, and the heat exchanger water outlet 42 of the waste heat recovery heat exchanger 40 is connected to the condenser water inlet 11 of the condenser 10.

[0095] Figure 10 yes Figure 8 A block diagram of the system structure of yet another improved embodiment.

[0096] In some embodiments, such as Figure 11 As shown, the heat source 70 is a heat pump and also includes a low-temperature water inlet 74 and a low-temperature water outlet 75. The low-temperature water outlet 75 is connected to the heat exchanger water inlet 41 of the waste heat recovery heat exchanger 40 of the flue gas treatment system, and the low-temperature water inlet 74 is connected to the heat exchanger water outlet 42 of the waste heat recovery heat exchanger 40 of the flue gas treatment system.

[0097] The low-temperature water inlet 74 and the low-temperature water outlet 75 are mainly used to convert the low-grade heat in the waste heat recovery heat exchanger 40 into high-grade heat that can be used by the heat pump through the heat pump.

[0098] Figure 11 It is a flow chart of the flue gas treatment method of the present application.

[0099] like Figure 11 As shown, a flue gas treatment method includes:

[0100] S110: receiving high-temperature flue gas and a first concentrated liquid through a contact heat exchange tower, cooling the high-temperature flue gas through heat exchange to form a second-high-temperature flue gas, and further concentrating the first concentrated liquid to form a second concentrated liquid;

[0101] S120: receiving the sub-high temperature flue gas through a waste heat recovery heat exchanger, absorbing waste heat in the sub-high temperature flue gas through heat exchange, and forming flue gas condensate;

[0102] S130: heating and evaporating the received flue gas condensate through an evaporator to form steam and a first concentrated liquid, and sending the first concentrated liquid into the contact heat exchange tower;

[0103] S140: The steam received from the evaporator is condensed by the condenser to form condensed water and then output.

[0104] In some embodiments, a flue gas treatment method includes:

[0105] S150: performing solid-liquid separation on the second concentrated liquid received from the contact heat exchange tower through a solid-liquid separation device.

[0106] It should be understood that the above-mentioned specific embodiments of the present application are merely illustrative or explain the principles of the present application and do not constitute a limitation of the present application. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present application should be included in the scope of protection of the present application. In addition, the claims attached hereto are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A flue gas treatment system, characterized in that: It includes a contact heat exchange tower, a waste heat recovery heat exchanger, an evaporator, a condenser, a heat source and a heat network; the contact heat exchange tower receives high-temperature flue gas and a first concentrated liquid through the flue gas inlet of the heat exchange tower and the concentrated liquid inlet of the heat exchange tower, respectively, and forms sub-high-temperature flue gas and a second concentrated liquid through heat exchange; the waste heat recovery heat exchanger receives the sub-high-temperature flue gas and the hot water through the flue gas inlet of the heat exchanger and the water inlet of the heat exchanger, respectively, and forms flue gas condensate and low-temperature flue gas directly discharged into the atmosphere through heat exchange; the evaporator receives the flue gas condensate and high-temperature hot water through the first water inlet of the evaporator and the second water inlet of the evaporator, respectively, and forms steam and the first concentrated liquid through evaporation; the condenser receives the steam through the condenser steam inlet, receives low-temperature hot water through the condenser water inlet, discharges the low-temperature hot water whose temperature is increased after heat exchange through the condenser water outlet, and discharges the condenser condensate formed by the steam through the heat exchange through the condenser condensate outlet; The contact heat exchange tower includes a heat exchange tower concentrated liquid outlet, and the flue gas treatment system also includes a solid-liquid separation device, the concentrated liquid inlet of the solid-liquid separation device is connected to the heat exchange tower concentrated liquid outlet, for receiving the second concentrated liquid; The waste heat recovery heat exchanger includes a flue gas condensate water outlet, the evaporator is a multi-stage evaporator, and each stage of the multi-stage evaporator includes an evaporator first water inlet and an evaporator first water outlet, the evaporator first water inlet is connected in parallel with the flue gas condensate water outlet, and the evaporator first water outlet is connected in parallel with the heat exchange tower concentrate inlet; The condenser further comprises a second water inlet of the condenser, which is connected to the condensed water outlet of the evaporator of at least one stage of the multi-stage evaporator; The first water outlet of the evaporator of the previous stage evaporator in the multi-stage evaporator is cascaded with the first water inlet of the evaporator of the next stage evaporator, wherein the first water inlet of the evaporator of the first stage evaporator is connected to the flue gas condensate outlet of the waste heat recovery heat exchanger, and the first water outlet of the evaporator of the last stage evaporator is connected to the heat exchange tower concentrate inlet of the contact heat exchange tower; The high-temperature flue gas outlet of the heat source is connected to the flue gas inlet of the heat exchange tower of the contact heat exchange tower, the water inlet of the heat source is connected to the condenser water outlet of the condenser, and the water outlet of the heat source is connected to the second water inlet of the evaporator; The water supply port of the heating network is communicated with the second water outlet of the evaporator, and the water return port of the heating network is communicated with the condenser water inlet of the condenser.

2. The flue gas treatment system according to claim 1, characterized in that: Each stage of the multi-stage evaporator includes a first water inlet of the evaporator, a second water inlet of the evaporator, a first water outlet of the evaporator, a second water outlet of the evaporator and an evaporator steam outlet; starting from the second stage of the multi-stage evaporator, the second water inlet of each stage of the evaporator is converted into an evaporator steam inlet, the second water outlet of the evaporator is converted into an evaporator condensate outlet, and starting from the second stage, the evaporator steam inlet of each stage of the evaporator is connected to the evaporator steam outlet of the previous stage of the evaporator.

3. The flue gas treatment system according to claim 2, characterized in that: The multi-stage evaporator starts from the second-stage evaporator and does not include the last-stage evaporator. The evaporator condensate outlet of each stage evaporator is connected to a flash tank, and the flash tank water inlet of the flash tank is connected to the evaporator condensate outlet of the evaporator at this stage; the flash tank steam outlet of the flash tank is connected to the evaporator steam inlet of the next stage evaporator.

4. The flue gas treatment system according to claim 3, characterized in that: The flash tank water outlet of the previous flash tank is connected to the flash tank water inlet of the next flash tank, and the water in the flash tanks of each stage is output from front to back.

5. The flue gas treatment system according to claim 2, characterized in that: The multi-stage evaporator starts from the second-stage evaporator, and the steam outlet of each stage evaporator is connected to a heater, and the heater water inlet of the heater is connected to the evaporator condensate outlet of the next stage evaporator; the heater steam inlet of the heater is connected to the evaporator steam outlet of the current stage evaporator.

6. The flue gas treatment system according to claim 5, characterized in that: The heater water outlet of the rear heater is connected to the heater water inlet of the front heater, and the hot water formed in each stage of the heater is output from the rear to the front.

7. The flue gas treatment system according to claim 5, characterized in that: The condensate outlet of the condenser is communicated with the heater water inlet of the last-stage heater, and the condensate formed in the condenser is fed into the last-stage heater through the heater water inlet.

8. The flue gas treatment system according to claim 1, characterized in that: It also includes a heat exchanger, wherein the first water inlet of the heat exchanger is connected to the condenser condensate outlet of the condenser for receiving the condenser condensate; the first water outlet of the heat exchanger is used to discharge the condenser condensate whose temperature is reduced after heat exchange; the second water inlet of the heat exchanger is connected to the flue gas condensate outlet of the waste heat recovery heat exchanger for receiving the flue gas condensate; the second water outlet of the heat exchanger is connected to the evaporator first inlet of the evaporator for outputting the flue gas condensate whose temperature is increased after heat exchange to the evaporator.

9. The flue gas treatment system according to any one of claims 1 to 8, characterized in that: The low-temperature hot water received by the condenser and the hot water received by the waste heat recovery heat exchanger come from the same water source.

10. The flue gas treatment system according to claim 1, characterized in that: The waste heat recovery heat exchanger is also passed between the return water port of the heat network and the condenser water inlet of the condenser. The return water port is connected to the heat exchanger water inlet of the waste heat recovery heat exchanger, and the heat exchanger water outlet of the waste heat recovery heat exchanger is connected to the condenser water inlet of the condenser.

11. The flue gas treatment system according to claim 1, characterized in that: The heat source further includes a low-temperature water inlet and a low-temperature water outlet, wherein the low-temperature water outlet is connected to the heat exchanger water inlet of the waste heat recovery heat exchanger, and the low-temperature water inlet is connected to the heat exchanger water outlet of the waste heat recovery heat exchanger.

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