Flue gas carbon capture system with waste heat recovery function

Abstract

The utility model relates to a flue gas carbon capture system with a waste heat recovery function. The flue gas carbon capture system with the waste heat recovery function comprises a washing tower, an absorption tower, a regeneration tower, a first evaporator, a compressor, temperature and pressure reduction equipment and a condenser, the first evaporator is provided with a first working medium inlet and a first working medium outlet, and the condenser is provided with a second working medium inlet and a second working medium outlet. The second working medium outlet, the temperature and pressure reduction equipment, the first working medium inlet, the first working medium outlet, the compressor and the second working medium inlet are sequentially communicated to form a working medium circulation loop, the working medium side of the condenser is a heat release side, and the absorbent side of the condenser is a heat absorption side. According to the flue gas carbon capture system with the waste heat recovery function, waste heat generated in the system can be recovered, the waste heat is used for the flue gas carbon capture system nearby, the use amount of cooling water is reduced, energy consumption is reduced, the problems of large public resource consumption and high operation cost are solved, and the flue gas carbon capture system has good flexibility and universality.

Description

TECHNICAL FIELD

[0001] The utility model relates to energy -conserving and emission reduction and cost reduction and benefit increasing technical field, concretely relates to a flue gas carbon capture system with waste heat recovery. BACKGROUND

[0002] The chemical absorption and desorption technology of carbon dioxide is a key carbon capture method, which realizes the capture of carbon dioxide by the chemical reaction of the chemical absorbent and carbon dioxide, and realizes the recycling of the absorbent by reversing the reaction under specific conditions. In the related art, the carbon dioxide chemical absorption and desorption system has the following problems: high comprehensive energy consumption, especially the need for high-temperature heat energy in the regeneration tower desorption stage of carbon dioxide; low waste heat recovery rate, especially the low-temperature reaction heat generated in the absorption tower capture stage of carbon dioxide, which is mostly removed by cooling water; large cooling water consumption. Some methods in the related art recover waste heat by coupling the front and rear processes to improve the energy efficiency of the entire system, but this method has the disadvantages of complex system, high control difficulty, low flexibility and universality. SUMMARY

[0003] The utility model aims at at least in a certain extent solves one of the technical problems in the related art.

[0004] Therefore, the embodiment of the utility model provides a flue gas carbon capture system with waste heat recovery, which can recover the waste heat generated in the system and use the waste heat in the flue gas carbon capture system itself, reducing the amount of cooling water, reducing energy consumption, reducing the problem of large public resource consumption and high operating cost, and the arrangement of the first evaporator and the condenser has little effect on the related equipment of the scrubbing tower, the absorption tower and the regeneration tower, the related pipeline installation and layout are simple, the control of the working medium circulation loop is affected by few factors, the control is simple, and the flue gas carbon capture system with waste heat recovery has good flexibility and universality.

[0005] The flue gas carbon capture system with waste heat recovery according to the embodiment of the utility model comprises:

[0006] The scrubbing tower has a first flue gas inlet, a first flue gas outlet, a scrubbing liquid inlet and a scrubbing liquid outlet;

[0007] The absorption tower has a second flue gas inlet, a second flue gas outlet, a first lean liquid inlet and a first rich liquid outlet, and the second flue gas inlet is communicated with the first flue gas outlet;

[0008] The regeneration tower has a first regeneration gas outlet, a first condensate liquid inlet, a first rich liquid inlet, a first lean liquid outlet, a first absorbent inlet and a first absorbent outlet, the first lean liquid outlet is communicated with the first lean liquid inlet, and the first rich liquid outlet is communicated with the first rich liquid inlet;

[0009] a first evaporator having a third flue gas inlet, a third flue gas outlet, a first working medium inlet and a first working medium outlet, the third flue gas inlet being configured to connect to a flue gas source, the third flue gas outlet being in communication with the first flue gas inlet;

[0010] a compressor and a temperature and pressure reducing device; and,

[0011] a condenser having a second absorbent inlet, a second absorbent outlet, a second working medium inlet and a second working medium outlet, the second absorbent inlet being in communication with the first absorbent outlet, the second absorbent outlet being in communication with the first absorbent inlet, the second working medium outlet, the temperature and pressure reducing device, the first working medium inlet, the first working medium outlet, the compressor and the second working medium inlet being sequentially in communication to form a working medium circulation loop, a working medium side of the condenser being a heat releasing side, and an absorbent side of the condenser being a heat absorbing side.

[0012] The flue gas carbon capture system with waste heat recovery can recover the waste heat generated in the system and use the waste heat in the flue gas carbon capture system, thereby reducing the amount of cooling water, reducing energy consumption, reducing the problem of large public resource consumption and high operating cost, and the arrangement of the first evaporator and the condenser has little effect on the related equipment of the scrubbing tower, the absorption tower and the regeneration tower, the related pipeline installation and layout are simple, the control of the working medium circulation loop is affected by few factors, the control is simple, has good flexibility and universality.

[0013] In some embodiments, the flue gas carbon capture system with waste heat recovery further comprises a lean-rich liquid heat exchanger having a first heat absorbing side inlet, a first heat absorbing side outlet, a first heat releasing side inlet and a first heat releasing side outlet, the first heat absorbing side inlet being in communication with the first rich liquid outlet, the first heat absorbing side outlet being in communication with the first rich liquid inlet, the first heat releasing side inlet being in communication with the first lean liquid outlet, and the first heat releasing side outlet being in communication with the first lean liquid inlet.

[0014] In some embodiments, the flue gas carbon capture system with waste heat recovery further comprises a second evaporator having a second lean liquid inlet, a second lean liquid outlet, a third working medium inlet and a third working medium outlet, the second lean liquid inlet being in communication with the first heat releasing side outlet, the second lean liquid outlet being in communication with the first lean liquid inlet, the third working medium inlet being in communication with the outlet of the temperature and pressure reducing device, and the third working medium outlet being in communication with the first working medium inlet.

[0015] In some embodiments, the flue gas carbon capture system with waste heat recovery further comprises a first regenerator having a second heat absorption side inlet, a second heat absorption side outlet, a second heat release side inlet and a second heat release side outlet, the second heat absorption side inlet being in communication with the first working medium outlet, the second heat absorption side outlet being in communication with the inlet of the compressor, the second heat release side inlet being in communication with the second working medium outlet, and the second heat release side outlet being in communication with the inlet of the pressure-reducing and temperature-reducing device.

[0016] In some embodiments, the flue gas carbon capture system with waste heat recovery, the pressure-reducing and temperature-reducing device is a throttle valve.

[0017] In some embodiments, the flue gas carbon capture system with waste heat recovery further comprises a gas-liquid separator having a fourth regenerator gas inlet, a fourth regenerator gas outlet and a third condensate liquid outlet, the fourth regenerator gas inlet being in communication with the first regenerator gas outlet, and the third condensate liquid outlet being in communication with the first condensate liquid inlet.

[0018] In some embodiments, the flue gas carbon capture system with waste heat recovery further comprises a second regenerator having a third heat absorption side inlet, a third heat absorption side outlet, a third heat release side inlet and a third heat release side outlet, the third heat release side inlet being in communication with the first regenerator gas outlet, the third heat release side outlet being in communication with the fourth regenerator gas inlet, the third heat absorption side inlet being in communication with the third condensate liquid outlet, and the third heat absorption side outlet being in communication with the first condensate liquid inlet.

[0019] In some embodiments, the flue gas carbon capture system with waste heat recovery further comprises a regenerator gas cooler having a fourth heat release side inlet and a fourth heat release side outlet, the fourth heat release side inlet being in communication with the third heat release side outlet, and the fourth heat release side outlet being in communication with the fourth regenerator gas inlet.

[0020] In some embodiments, the flue gas carbon capture system with waste heat recovery further comprises a reboiler, the inlet of the reboiler being in communication with the second absorbent outlet, and the outlet of the reboiler being in communication with the first absorbent inlet. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structure schematic diagram of the flue gas carbon capture system with waste heat recovery of the embodiment of the utility model;

[0022] Figure 2 is an example schematic diagram of the flue gas carbon capture system with waste heat recovery of the embodiment of the utility model.

[0023] REFERENCE NUMERALS:

[0024] Flue gas carbon capture system 100;

[0025] Washing tower 1, first flue gas inlet 101, first flue gas outlet 102, washing liquid inlet 103, washing liquid outlet 104;

[0026] Absorption tower 2, second flue gas inlet 201, second flue gas outlet 202, first lean liquid inlet 203, first rich liquid outlet 204;

[0027] Regeneration tower 3, first regeneration gas outlet 301, first condensate inlet 302, first rich liquid inlet 303, first lean liquid outlet 304, first absorbent inlet 305, first absorbent outlet 306;

[0028] First evaporator 4, third flue gas inlet 401, third flue gas outlet 402, first working medium inlet 403, first working medium outlet 404;

[0029] Compressor 5, temperature and pressure reducing device 6;

[0030] Condenser 7, second absorbent inlet 701, second absorbent outlet 702, second working medium inlet 703, second working medium outlet 704;

[0031] First regenerator 8, second heat absorption side inlet 801, second heat absorption side outlet 802, second heat release side inlet 803, second heat release side outlet 804;

[0032] Second evaporator 9, second lean liquid inlet 901, second lean liquid outlet 902, third working medium inlet 903, third working medium outlet 904;

[0033] Lean and rich liquid heat exchanger 10, first heat absorption side inlet 1001, first heat absorption side outlet 1002, first heat release side inlet 1003, first heat release side outlet 1004;

[0034] Boost fan 11;

[0035] Second regenerator 12, third heat absorption side inlet 1201, third heat absorption side outlet 1202, third heat release side inlet 1203, third heat release side outlet 1204;

[0036] Gas-liquid separator 13, regeneration gas cooler 14, reboiler 15, washing liquid cooler 16, lean liquid cooler 17. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0038] AsFigure 1 The utility model discloses a flue gas carbon capture system 100 with waste heat recovery, comprising a scrubber 1, an absorber 2, a regenerator 3, a first evaporator 4, a compressor 5, a temperature and pressure reducing device 6 and a condenser 7.

[0039] The scrubber 1 has a first flue gas inlet 101, a first flue gas outlet 102, a scrubbing liquid inlet 103 and a scrubbing liquid outlet 104. The scrubbing liquid enters the scrubber 1 from the scrubbing liquid inlet 103, and the flue gas enters the scrubber 1 from the first flue gas inlet 101. After being washed, the flue gas removes dust and soluble gas and is discharged from the first flue gas outlet 102. After washing the flue gas, the temperature of the scrubbing liquid rises, and the scrubbing liquid is discharged from the scrubbing liquid outlet 104. The scrubbing liquid is replaced and supplemented regularly. The scrubber 1 is gas-liquid countercurrent, the flue gas flows from bottom to top, and the scrubbing liquid flows from top to bottom.

[0040] The absorber 2 has a second flue gas inlet 201, a second flue gas outlet 202, a first lean liquid inlet 203 and a first rich liquid outlet 204, and the second flue gas inlet 201 is communicated with the first flue gas outlet 102. The flue gas discharged from the first flue gas outlet 102 enters the absorber 2 through the second flue gas inlet 201. The absorber 2 performs chemical absorption of carbon dioxide on the flue gas. The purified flue gas is discharged from the second flue gas outlet 202, and the purified flue gas is processed according to the requirements of the site. The lean liquid flows into the absorber 2 from the first lean liquid inlet 203, becomes rich liquid after absorbing carbon dioxide in the absorber 2, and is discharged from the first rich liquid outlet 204 at the bottom of the absorber 2. The absorber 2 is gas-liquid countercurrent, the flue gas flows from bottom to top, and the absorbent flows from top to bottom.

[0041] The regenerator 3 has a first regenerated gas outlet 301, a first condensed liquid inlet 302, a first rich liquid inlet 303, a first lean liquid outlet 304, a first absorbent inlet 305 and a first absorbent outlet 306. The first lean liquid outlet 304 is communicated with the first lean liquid inlet 203, and the first rich liquid outlet 204 is communicated with the first rich liquid inlet 303. The rich liquid flows into the regenerator 3 from the first rich liquid outlet 204 through the first rich liquid inlet 303, becomes lean liquid after desorbing carbon dioxide in the regenerator 3, and is discharged from the first lean liquid outlet 304 at the bottom of the regenerator 3 to the absorber 2, forming a circulation of lean and rich liquid. The desorbed carbon dioxide regenerated gas is discharged from the first regenerated gas outlet 301 at the top of the regenerator 3. The absorbent is discharged from the first absorbent outlet 306. The regenerator 3 is gas-liquid countercurrent, the regenerated gas carbon dioxide flows from bottom to top, and the absorbent flows from top to bottom.

[0042] The first evaporator 4 has a third flue gas inlet 401, a third flue gas outlet 402, a first working medium inlet 403 and a first working medium outlet 404, the third flue gas inlet 401 is used for connecting a flue gas source, the third flue gas outlet 402 is communicated with the first flue gas inlet 101, flue gas flows through the heat releasing side of the first evaporator 4, and enters the scrubbing tower 1 after heat releasing of the first evaporator 4. The condenser 7 has a second absorbent inlet 701, a second absorbent outlet 702, a second working medium inlet 703 and a second working medium outlet 704, the second absorbent inlet 701 is communicated with the first absorbent outlet 306, the second absorbent outlet 702 is communicated with the first absorbent inlet 305, the second working medium outlet 704, the pressure reducing and temperature reducing device 6, the first working medium inlet 403, the first working medium outlet 404, the compressor 5 and the second working medium inlet 703 are sequentially communicated to form a working medium circulation loop, the working medium side of the condenser 7 is a heat releasing side, and the absorbent side of the condenser 7 is a heat absorbing side. Then, the working medium circulates through the second working medium outlet 704 of the condenser 7, the inlet of the pressure reducing and temperature reducing device 6, the outlet of the pressure reducing and temperature reducing device 6, the first working medium inlet 403 of the first evaporator 4, the first working medium outlet 404, the inlet of the compressor 5, the outlet of the compressor 5 and the second working medium inlet 703 in sequence.

[0043] The application method of the flue gas carbon capture system 100 with waste heat recovery in the embodiment of the utility model, comprising the following steps: introducing working medium into the working medium circulation loop, the working medium enters the first evaporator 4 to absorb heat, recovers the heat energy of flue gas, then enters the compressor 5, is pressurized and heated by the compressor 5, then enters the heat releasing side of the condenser 7, heats the absorbent entering the regenerator 3, then enters the pressure reducing and temperature reducing device 6, and the working medium after temperature reduction and pressure reduction enters the first evaporator 4.

[0044] The working medium circulates in the working medium circulation loop, when flowing through the first evaporator 4, exchanges heat with flue gas located at the heat releasing side, is heated to form gaseous working medium after absorbing the heat energy of flue gas, then flows through the compressor 5, is pressurized and heated by the compressor to form high-temperature and high-pressure gaseous working medium, and then the high-temperature and high-pressure gaseous working medium enters the condenser 7. The absorbent flows out from the first absorbent outlet 306, enters the condenser 7 through the second absorbent inlet 701, in the condenser 7, the high-temperature and high-pressure gaseous working medium heats the absorbent once, the absorbent is heated once by the condenser 7, returns to the regenerator 3 from the first absorbent inlet 305, the gaseous working medium is condensed or cooled by the condenser 7 to form high-temperature liquid working medium, the high-temperature liquid working medium enters the pressure reducing and temperature reducing device 6 to reduce temperature and pressure, and then forms low-temperature and low-pressure liquid working medium to reabsorb heat and gasify and heat up in the first evaporator 4.

[0045] The flue gas carbon capture system 100 with waste heat recovery provided by the embodiment of the utility model, the working medium circulation loop is arranged, the working medium passes through the first evaporator 4 and the condenser 7, on the one hand, the waste heat of the flue gas is recovered, the flue gas cooler of the washing tower 1 in the prior art is replaced, the problem of cooling water is reduced, on the other hand, the recovered waste heat is pressurized and heated after the compressor 5, the absorbent of the regenerator 3 is heated, the temperature of the absorbent entering the regenerator 3 is improved, thereby the heat energy consumed for improving the temperature of the absorbent is reduced, the problem of high energy consumption is reduced, thereby the operation cost of the flue gas carbon capture system 100 is reduced.

[0046] Therefore, the flue gas carbon capture system 100 with waste heat recovery provided by the embodiment of the utility model can recover the waste heat generated in the system 100 and use the waste heat in the flue gas carbon capture system 100 itself, reduce the amount of cooling water, reduce energy consumption, reduce the problems of large public resource consumption and high operation cost, meanwhile, the arrangement of the first evaporator 4 and the condenser 7 has little influence on the related equipment of the washing tower 1, the absorption tower 2 and the regenerator 3, the related pipeline installation and layout are simple, the control of the working medium circulation loop is affected by few factors, the control is simple, and the flue gas carbon capture system 100 has good flexibility and universality.

[0047] In order to make the scheme of the application easier to understand, the temperature of the original flue gas entering the flue gas carbon capture system 100 is taken as 75-85 DEG C for example.

[0048] The flue gas carbon capture system 100 with waste heat recovery provided by the embodiment of the utility model comprises a washing tower 1, an absorption tower 2, a regenerator 3, a first evaporator 4, a compressor 5, a condenser 7, a temperature and pressure reducing device 6, a first heat exchanger 8, a second evaporator 9, a lean and rich liquid heat exchanger 10, a booster fan 11, a second heat exchanger 12, a gas-liquid separator 13, a regenerated gas cooler 14, a reboiler 15, a lean liquid cooler 17, a washing liquid cooler 16, the booster fan 11, a rich liquid pump, a lean liquid pump and an absorbent pump.

[0049] The washing tower 1 has a first flue gas inlet 101, a first flue gas outlet 102, a washing liquid inlet 103 and a washing liquid outlet 104. The booster fan 11 is arranged at the flue gas inlet side of the washing tower 1, the inlet of the booster fan 11 is communicated with the original flue gas source, the outlet of the booster fan 11 is communicated with the third flue gas inlet 401 of the first evaporator 4, and the third flue gas outlet 402 of the first evaporator 4 is communicated with the first flue gas inlet 101. The original flue gas increases power through the booster fan 11 and then enters the washing tower 1 after the cold zone of the first evaporator 4. The temperature of the flue gas discharged from the first flue gas outlet 102 of the washing tower 1 is about 40 DEG C, and the temperature of the washing liquid discharged from the washing liquid outlet 104 is about 40-50 DEG C.

[0050] The scrubbing liquid cooler 16 has a sixth heat releasing side inlet and a sixth heat releasing side outlet, the inlet of the scrubbing liquid pump is communicated with the scrubbing liquid outlet 104, the outlet of the scrubbing liquid pump is communicated with the sixth heat releasing side inlet, and the sixth heat releasing outlet is communicated with the scrubbing liquid outlet 104. The scrubbing liquid is recycled. The heat absorbing side of the scrubbing liquid cooler 16 is communicated with an external cooling water pipeline.

[0051] The absorption tower 2 has a second flue gas inlet 201, a second flue gas outlet 202, a first lean liquid inlet 203, a first rich liquid outlet 204, a desalted water supplement inlet and an absorbent blowdown outlet, and the second flue gas inlet 201 is communicated with the first flue gas outlet 102. The flue gas discharged through the first flue gas outlet 102 enters the absorption tower 2 through the second flue gas inlet 201, the purified flue gas discharged through the second flue gas outlet 202 has a temperature of 50-55℃, and the rich liquid discharged through the first rich liquid outlet 204 has a temperature of 50-55℃.

[0052] The regeneration tower 3 has a first regenerated gas outlet 301, a first condensed liquid inlet 302, a first rich liquid inlet 303, a first lean liquid outlet 304, a first absorbent inlet 305 and a first absorbent outlet 306, the first lean liquid outlet 304 is communicated with the first lean liquid inlet 203, and the first rich liquid outlet 204 is communicated with the first rich liquid inlet 303.

[0053] The lean-rich liquid heat exchanger 10 has a first heat absorbing side inlet 1001, a first heat absorbing side outlet 1002, a first heat releasing side inlet 1003 and a first heat releasing side outlet 1004, the first heat absorbing side inlet 1001 is communicated with the first rich liquid outlet 204, the first heat absorbing side outlet 1002 is communicated with the first rich liquid inlet 303, the first heat releasing side inlet 1003 is communicated with the first lean liquid outlet 304, and the first heat releasing side outlet 1004 is communicated with the first lean liquid inlet 203.

[0054] The rich liquid discharged from the absorption tower 2 flows through the heat absorbing side of the lean-rich liquid heat exchanger 10, and the temperature of the rich liquid is increased to 100-105℃ after heat absorption. The rich liquid at a temperature of 100-105℃ enters the regeneration tower 3 from the first rich liquid inlet 303. After the rich liquid is resolved into carbon dioxide, the lean liquid is discharged from the first lean liquid outlet 304 at the bottom of the regeneration tower 3, and the temperature of the lean liquid is 110-115℃. The high-temperature lean liquid enters the heat releasing side of the lean-rich liquid heat exchanger 10, and the temperature of the lean liquid is reduced to 60-65℃ after heat release, and then the lean liquid flows to the first lean liquid inlet 203 of the absorption tower 2. The carbon dioxide regenerated gas is discharged from the first regenerated gas outlet 301 at the top of the regeneration tower 3, the temperature of the carbon dioxide regenerated gas is 98-102℃, and the pressure is 0.06Mpa. The absorbent of the regeneration tower 3 is discharged from the first absorbent outlet 306, and the temperature of the absorbent is about 112℃.

[0055] The lean-rich liquid heat exchanger 10 exchanges heat between the high-temperature lean liquid generated by the regeneration tower 3 and the low-temperature rich liquid generated by the absorption tower 2, realizes preheating and temperature rising of the rich liquid and first cooling and temperature reduction of the lean liquid, realizes recovery of the waste heat of the lean liquid and heating of the rich liquid, further uses the waste heat in the flue gas carbon capture system 100 itself, further reduces the amount of cooling water, further reduces energy consumption, and further reduces the problems of large public resource consumption and high operating cost.

[0056] Specifically, the rich liquid pump is connected to the first rich liquid outlet 204 of the absorption tower 2 and the first heat absorption side inlet 1001 of the lean-rich liquid heat exchanger 10, and the rich liquid pump pressurizes the rich liquid to provide circulating power for the rich liquid.

[0057] Specifically, the lean liquid pump is connected to the first heat release side outlet 1004 of the lean-rich liquid heat exchanger 10 and the first lean liquid inlet 203 of the absorption tower 2, and the lean liquid pump pressurizes the lean liquid to provide circulating power for the lean liquid.

[0058] The condenser 7 has a second absorbent inlet 701, a second absorbent outlet 702, a second working medium inlet 703, and a second working medium outlet 704. The second absorbent inlet 701 is connected to the first absorbent outlet 306 of the regeneration tower 3, and the second absorbent outlet 702 is connected to the first absorbent inlet 305 of the regeneration tower 3. The working medium side of the condenser 7 is the heat release side, and the absorbent side of the condenser 7 is the heat absorption side. The absorbent discharged from the regeneration tower 3 enters the heat absorption side of the condenser 7 and exchanges heat with the gaseous working medium of the heat release side of the condenser 7, and the temperature rises. The working medium discharged from the heat release side of the condenser 7 is liquid working medium.

[0059] The inlet of the reboiler 15 is connected to the second absorbent outlet 702, the outlet of the reboiler 15 is connected to the inlet of the absorbent pump, and the outlet of the absorbent pump is connected to the first absorbent inlet 305 of the regeneration tower 3. The absorbent discharged from the second absorption outlet of the condenser 7 is heated once in the condenser 7, then enters the reboiler 15 for secondary heating, and the temperature of the absorbent after secondary heating is about 135℃, and then enters the regeneration tower 3. The absorbent pump provides power for the circulation of the absorbent and returns the heated absorbent to the regeneration tower 3.

[0060] Specifically, the reboiler 15 adopts heating methods such as steam heating, electric heating, or combustion heating.

[0061] Specifically, the absorbent is selected according to the original flue gas condition and product demand, and the absorbent can be piperazine, alcohol amine absorbent, or a complex absorbent.

[0062] The second evaporator 9, the first evaporator 4, the first regenerator 8, the compressor 5, the condenser 7, and the temperature and pressure reducing device 6 are all located on the working medium circulation loop.

[0063] The second evaporator 9 has a second lean liquid inlet 901, a second lean liquid outlet 902, a third working medium inlet 903 and a third working medium outlet 904. The second lean liquid inlet 901 is communicated with the first heat releasing side outlet 1004 of the lean-liquid-rich heat exchanger 10. The second lean liquid outlet 902 is communicated with the first lean liquid inlet 203. The third working medium inlet 903 is communicated with the outlet of the temperature and pressure reducing device 6. The third working medium outlet 904 is communicated with the first working medium inlet 403.

[0064] The working medium discharged from the condenser 7 is liquid working medium. After passing through the temperature and pressure reducing device 6, the temperature and pressure of the liquid working medium are reduced to form low-temperature liquid working medium. Then the low-temperature liquid working medium enters the heat absorbing side of the second evaporator 9 through the third working medium inlet 903, exchanges heat with the lean liquid on the heat releasing side of the second evaporator 9, recovers the heat energy of the lean liquid, and heats the low-temperature liquid working medium once to increase the temperature of the working medium, forming gas-liquid mixed working medium which is then discharged from the third working medium outlet 904.

[0065] The second evaporator 9 further recovers the waste heat of the lean liquid, thereby further using the waste heat for the system 100 itself, further reducing the amount of cooling water for cooling the lean liquid, further reducing energy consumption, and further reducing the problems of large consumption of public resources and high operating cost.

[0066] The first evaporator 4 has a third flue gas inlet 401, a third flue gas outlet 402, a first working medium inlet 403 and a first working medium outlet 404. The third flue gas inlet 401 is communicated with the outlet of the booster fan 11. The third flue gas outlet 402 is communicated with the first flue gas inlet 101 of the scrubbing tower 1. The flue gas flows through the heat releasing side of the first evaporator 4. The working medium discharged from the second evaporator 9 enters the heat absorbing side of the first evaporator 4 through the first working medium inlet 403. The flue gas and the working medium exchange heat, and the flue gas after being cooled enters the scrubbing tower 1, thereby increasing the temperature of the gas-liquid mixed working medium to form pure gaseous working medium. The first evaporator 4 recovers the heat energy of the flue gas to heat the low-temperature gas-liquid mixed working medium twice.

[0067] The first regenerator 8 has a second heat absorbing side inlet 801, a second heat absorbing side outlet 802, a second heat releasing side inlet 803 and a second heat releasing side outlet 804. The second heat absorbing side inlet 801 is communicated with the first working medium outlet 404. The second heat absorbing side outlet 802 is communicated with the inlet of the compressor 5. The second heat releasing side inlet 803 is communicated with the second working medium outlet 704. The second heat releasing side outlet 804 is communicated with the inlet of the temperature and pressure reducing device 6.

[0068] The gas-liquid mixed working medium discharged from the first evaporator 4 enters the heat absorption side of the first regenerator 8, and the high-temperature liquid working medium discharged from the condenser 7 enters the heat release side of the first regenerator 8. The higher-temperature liquid working medium discharged from the condenser 7 further heats the gaseous working medium discharged from the first evaporator 4, so as to: 1. increase the superheat degree of the gaseous working medium, thereby increasing the thermal energy of the working medium gas entering the compressor 5, reducing the energy consumption of the compressor 5, and reducing the liquid damage of the compressor 5, thereby further reducing the energy consumption of the system 100, improving the energy efficiency of the flue gas carbon capture system 100, and further reducing the operation cost of the flue gas carbon capture system 100; 2. reduce the temperature difference of the high-temperature liquid working medium when it is cooled by the temperature-reducing and pressure-reducing device 6, and also recover part of the heat of the high-temperature liquid working medium, thereby reducing the working strength of the temperature-reducing and pressure-reducing device 6 and reducing the waste of heat and pressure caused by the temperature-reducing and pressure-reducing of the high-temperature liquid working medium; 3. In this process, the carbon dioxide absorption and desorption process is not changed, and the heat exchange between the two working media with opposite flow directions is used to reduce the energy consumption, which further shows the flexibility and universality of the flue gas carbon capture system 100.

[0069] Specifically, the temperature-reducing and pressure-reducing device 6 is a throttle valve. The throttle valve has a simple structure and can achieve the temperature-reducing and pressure-reducing of the high-temperature liquid working medium required by the flue gas carbon capture system 100, and can also reduce the cost of the flue gas carbon capture system 100.

[0070] The second regenerator 12 has a third heat absorption side inlet 1201, a third heat absorption side outlet 1202, a third heat release side inlet 1203, and a third heat release side outlet 1204. The third heat release side inlet 1203 is in communication with the first regenerated gas outlet 301. The gas-liquid separator 13 has a fourth regenerated gas inlet, a fourth regenerated gas outlet, and a third condensed liquid outlet. The third heat release side outlet 1204 is in communication with the fourth regenerated gas inlet, the third condensed liquid outlet is in communication with the third heat absorption side inlet 1201, and the third heat absorption side outlet 1202 is in communication with the first condensed liquid inlet 302.

[0071] The regeneration gas discharged from the first regeneration gas outlet 301 of the regeneration tower 3 enters the second regenerator 12 through the third heat releasing side inlet 1203, and then enters the gas-liquid separator 13, in which product gas with a purity of 95% at a temperature of about 40°C and condensate at a temperature of about 45°C are generated. The product gas is discharged from the fourth regeneration gas outlet and processed according to user requirements. The condensate is discharged from the third condensate outlet and enters the second regenerator 12 through the third heat absorbing side inlet 1201, in which the condensate exchanges heat with the regeneration gas, achieving the cooling of the regeneration gas and the heating of the condensate. Thus, the temperature of the condensate entering the regeneration tower 3 is increased, and the heating energy provided by the reboiler 15 to ensure the temperature requirement in the regeneration tower 3 is reduced, thereby further reducing the energy consumption of the flue gas carbon capture system 100, further improving the energy efficiency of the flue gas carbon capture system 100, and further reducing the operating cost of the flue gas carbon capture system 100.

[0072] Specifically, the working medium is R1233zdE, HFC245ca or HFC245fa.

[0073] The compressor 5 is a centrifugal compressor 5, a scroll compressor 5 or a screw compressor 5, and can be installed with one-stage compression, two-stage compression or three-stage compression, which can be selected according to the site conditions and heating capacity requirements.

[0074] The regeneration gas cooler 14 has a fourth heat releasing side inlet and a fourth heat releasing side outlet, the fourth heat releasing side inlet is in communication with the third heat releasing side outlet 1204, and the fourth heat releasing side outlet is in communication with the fourth regeneration gas inlet. The regeneration gas cooler 14 is arranged between the heat releasing side of the second regenerator 12 and the gas-liquid separator 13, and performs secondary cooling on the regeneration gas.

[0075] The lean liquid cooler 17 has a fifth heat releasing side inlet and a fifth heat releasing side outlet, the fifth heat releasing side inlet is in communication with the second lean liquid outlet 902 of the second evaporator 9, and the fifth heat releasing side outlet is in communication with the first lean liquid inlet 203. The lean liquid cooler 17 performs three times of cooling on the lean liquid, and the temperature of the lean liquid cooled from the lean liquid cooler 17 is about 40°C.

[0076] Specifically, the second evaporator 9, the first evaporator 4, the scrubbing liquid cooler 16, the lean liquid cooler 17, the lean-rich liquid heat exchanger 10, the first regenerator 8, the second regenerator 12 and the regeneration gas cooler 14 all adopt a partition wall type heat exchanger, for example, a plate heat exchanger, a tube heat exchanger or a heat pipe heat exchanger, and the appropriate structure and heat exchange area are selected according to the site conditions and production requirements.

[0077] The working medium in the working medium circulation loop of the flue gas carbon capture system 100 first flows through the second evaporator 9, exchanges heat with lean liquid located at the heat releasing side of the second evaporator 9, is heated after absorbing heat energy of the lean liquid, and forms gas-liquid mixed working medium; then flows through the first evaporator 4, exchanges heat with flue gas located at the heat releasing side of the first evaporator 4, is heated after absorbing heat energy of the flue gas, and forms gaseous working medium; then flows through the heat absorbing side of the first regenerator 8, exchanges heat with hot working medium located at the heat releasing side of the first regenerator 8, and increases superheat degree after absorbing heat energy of the working medium. The compressor 5 pressurizes and heats the superheated gaseous working medium, and forms high-temperature and high-pressure gaseous working medium, and then the high-temperature and high-pressure gaseous working medium enters the condenser 7. The absorbent flows out from the first absorbent outlet 306, enters the condenser 7 through the second absorbent inlet 701, the high-temperature and high-pressure gaseous working medium heats the absorbent once in the condenser 7, the absorbent is heated once in the condenser 7 and returns to the regenerator 3 from the first absorbent inlet 305, the gaseous working medium is condensed or cooled in the condenser 7, and forms high-temperature liquid working medium, the high-temperature liquid working medium first enters the heat releasing side of the first regenerator 8 to reduce temperature, then enters the temperature and pressure reducing device 6 to further reduce temperature and pressure, and then forms low-temperature and low-pressure liquid working medium to enter the second evaporator 9 to be heated and gasified again.

[0078] The flue gas carbon capture system 100 of the embodiment of the utility model, the arrangement of the first evaporator 4, the second evaporator 9, the condenser 7 and the second regenerator 12 has little influence on the related equipment of the scrubbing tower 1, the absorption tower 2 and the regenerator 3, can directly transform the original traditional carbon capture system, adds the first evaporator 4, the second evaporator 9, the condenser 7 and the second regenerator 12 in the system, not only reduces the transformation range and cost to the maximum extent, but also through the working medium circulation loop formed by the condenser 7, the throttle valve, the second evaporator 9, the first evaporator 4, the first regenerator 8 and the compressor 5 and the second regenerator 12, the original flue gas, lean liquid and regenerated gas waste heat can be reused by itself, which can not only reduce the system energy consumption, water consumption and operation cost, but also ensure the supply and demand matching and temperature matching of heat supply. In addition, the flue gas carbon capture system 100 of the embodiment of the utility model does not need to be combined with other processes, and has high flexibility and universality.

[0079] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0080] In addition, the terms "first", "second", "third", etc. are used herein only to describe various features, and do not imply a relative importance or a specific order of the features. Thus, features defined with "first", "second", "third" can include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0081] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connection", "fixing" and the like should be interpreted in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected or can communicate with each other; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication or interaction relationship of two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0082] In the present application, unless otherwise specifically defined and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0083] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the description, the illustrative representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction.

[0084] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A flue gas carbon capture system (100) with waste heat recovery, characterized in that, Comprise: a washing tower (1) having a first flue gas inlet (101), a first flue gas outlet (102), a washing liquid inlet (103) and a washing liquid outlet (104); an absorption tower (2) having a second flue gas inlet (201), a second flue gas outlet (202), a first lean liquid inlet (203) and a first rich liquid outlet (204), the second flue gas inlet (201) being in communication with the first flue gas outlet (102); a regeneration tower (3) having a first regeneration gas outlet (301), a first condensate liquid inlet (302), a first rich liquid inlet (303), a first lean liquid outlet (304), a first absorbent inlet (305) and a first absorbent outlet (306), the first lean liquid outlet (304) being in communication with the first lean liquid inlet (203), and the first rich liquid outlet (204) being in communication with the first rich liquid inlet (303); a first evaporator (4) having a third flue gas inlet (401), a third flue gas outlet (402), a first working medium inlet (403) and a first working medium outlet (404), the third flue gas inlet (401) being used to connect a flue gas source, and the third flue gas outlet (402) being in communication with the first flue gas inlet (101); a compressor (5) and a temperature and pressure reducing device (6); and a condenser (7) having a second absorbent inlet (701), a second absorbent outlet (702), a second working medium inlet (703) and a second working medium outlet (704), the second absorbent inlet (701) being in communication with the first absorbent outlet (306), the second absorbent outlet (702) being in communication with the first absorbent inlet (305), the second working medium outlet (704), the temperature and pressure reducing device (6), the first working medium inlet (403), the first working medium outlet (404), the compressor (5) and the second working medium inlet (703) being in communication in sequence to form a working medium circulation loop, the working medium side of the condenser (7) being a heat releasing side, and the absorbent side of the condenser (7) being a heat absorbing side.

2. The flue gas carbon capture system (100) with heat recovery according to claim 1, characterized in that, Further comprising a lean and rich liquid heat exchanger (10) having a first heat absorbing side inlet (1001), a first heat absorbing side outlet (1002), a first heat releasing side inlet (1003) and a first heat releasing side outlet (1004), the first heat absorbing side inlet (1001) being in communication with the first rich liquid outlet (204), the first heat absorbing side outlet (1002) being in communication with the first rich liquid inlet (303), the first heat releasing side inlet (1003) being in communication with the first lean liquid outlet (304), and the first heat releasing side outlet (1004) being in communication with the first lean liquid inlet (203).

3. The flue gas carbon capture system (100) with heat recovery according to claim 2, characterized in that, Further comprising a second evaporator (9) having a second lean liquid inlet (901), a second lean liquid outlet (902), a third working medium inlet (903) and a third working medium outlet (904), the second lean liquid inlet (901) being in communication with the first heat releasing side outlet (1004), the second lean liquid outlet (902) being in communication with the first lean liquid inlet (203), the third working medium inlet (903) being in communication with the outlet of the pressure-reducing and temperature-reducing device (6), and the third working medium outlet (904) being in communication with the first working medium inlet (403).

4. The flue gas carbon capture system (100) with heat recovery according to claim 1, characterized in that, Further comprising a first regenerator (8) having a second heat absorbing side inlet (801), a second heat absorbing side outlet (802), a second heat releasing side inlet (803) and a second heat releasing side outlet (804), the second heat absorbing side inlet (801) being in communication with the first working medium outlet (404), the second heat absorbing side outlet (802) being in communication with the inlet of the compressor (5), the second heat releasing side inlet (803) being in communication with the second working medium outlet (704), and the second heat releasing side outlet (804) being in communication with the inlet of the pressure-reducing and temperature-reducing device (6).

5. The flue gas carbon capture system (100) with heat recovery according to claim 1, characterized in that, The pressure-reducing and temperature-reducing device (6) is a throttle valve.

6. The flue gas carbon capture system (100) with heat recovery according to claim 1, characterized in that, Further comprising a gas-liquid separator (13) having a fourth regenerating gas inlet, a fourth regenerating gas outlet and a third condensate liquid outlet, the fourth regenerating gas inlet being in communication with the first regenerating gas outlet (301), and the third condensate liquid outlet being in communication with the first condensate liquid inlet (302).

7. The flue gas carbon capture system (100) with heat recovery according to claim 6, characterized in that, Further comprising a second regenerator (12) having a third heat absorbing side inlet (1201), a third heat absorbing side outlet (1202), a third heat releasing side inlet (1203) and a third heat releasing side outlet (1204), the third heat releasing side inlet (1203) being in communication with the first regenerating gas outlet (301), the third heat releasing side outlet (1204) being in communication with the fourth regenerating gas inlet, the third heat absorbing side inlet (1201) being in communication with the third condensate liquid outlet, and the third heat absorbing side outlet (1202) being in communication with the first condensate liquid inlet (302).

8. The flue gas carbon capture system (100) with heat recovery according to claim 7, characterized in that, Further comprising a regenerating gas cooler (14) having a fourth heat releasing side inlet and a fourth heat releasing side outlet, the fourth heat releasing side inlet being in communication with the third heat releasing side outlet (1204), and the fourth heat releasing side outlet being in communication with the fourth regenerating gas inlet.

9. The flue gas carbon capture system (100) with heat recovery according to claim 1, characterized in that, Further comprising a reboiler (15), the inlet of the reboiler (15) being in communication with the second absorbent outlet (702), and the outlet of the reboiler (15) being in communication with the first absorbent inlet (305).

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