Waste heat utilization high-temperature heat pump carbon dioxide capture system

Abstract

The utility model provides a waste heat utilization high-temperature heat pump carbon dioxide capture system which is reasonable in structural design and reduces the operation cost of a chemical absorption method. The boiler is connected with the dust remover; the pretreatment tower is connected with the desulfurization tower and the absorption tower; the absorption tower is connected with the rich and lean liquid heat exchanger; the rich and lean liquid heat exchanger is connected with the regeneration tower; a solution outlet of the regeneration tower is connected with a solution inlet of the reboiler; a solution outlet of the reboiler is connected with a hot phase inlet of the lean and rich liquid heat exchanger; a hot phase outlet of the barren-rich liquid heat exchanger is connected with a hot phase inlet of the barren liquid cooler; a hot phase outlet of the barren liquid cooler is connected with a solution inlet of the absorption tower; a cold phase outlet of the barren liquor cooler is connected with a water spraying inlet of the pretreatment tower; a flue gas outlet of the dust remover is connected with a flue gas inlet of the flue gas heat exchanger, and a flue gas outlet of the flue gas heat exchanger is connected with a flue gas inlet of the desulfurizing tower; and the heat pump system is connected with the flue gas heat exchanger and the reboiler.

Description

Technical Field

[0001] The utility model relates to a waste heat utilization high temperature heat pump carbon dioxide capture system. Background Art

[0002] Carbon dioxide capture technology can effectively reduce carbon dioxide emissions from human activities such as industrial production and energy utilization, thereby slowing down the pace of global warming and protecting the ecological environment. According to United Nations statistics, if carbon capture and storage (CCS) technology is not adopted, the cost of achieving climate goals will increase by 138%. This shows that CCS technology plays an irreplaceable role in reducing emission reduction costs and achieving climate control goals.

[0003] However, the implementation cost of carbon dioxide capture technology is relatively high, including the cost of the entire process such as capture, transportation and storage, among which the cost of carbon dioxide capture technology accounts for the highest proportion. Currently, there are capture technologies before combustion, after combustion and oxygen-enriched combustion, and the most mature is post-combustion capture technology. The most mature technical route in post-combustion capture technology is chemical absorption. The highest operating cost in chemical absorption is regeneration steam, which accounts for more than 50% of the operating cost. Due to the high cost of steam, the cost of carbon dioxide capture in coal-fired power plants is about 300 yuan / t, which is not economical. It can be seen that reducing steam consumption and optimizing the regeneration heat method are the key to reducing the operating cost of chemical absorption. Utility Model Content

[0004] The purpose of the utility model is to overcome the above-mentioned deficiencies in the prior art and to provide a waste heat utilization high temperature heat pump carbon dioxide capture system which has a reasonable structural design and reduces the operating cost of the chemical absorption method.

[0005] The technical solution adopted by the utility model to solve the above problems is: a waste heat utilization high-temperature heat pump carbon dioxide capture system, including a boiler, a dust collector, a desulfurization tower and a carbon dioxide capture device, the carbon dioxide capture device including a pretreatment tower, an absorption tower, a regeneration tower, a lean-rich liquid heat exchanger, a lean liquid cooler and a reboiler; the flue gas outlet of the boiler is connected to the flue gas inlet of the dust collector; the flue gas inlet of the pretreatment tower is connected to the flue gas outlet of the desulfurization tower, and the flue gas outlet of the pretreatment tower is connected to the flue gas inlet of the absorption tower; the solution outlet of the absorption tower is connected to the water side inlet of the lean-rich liquid heat exchanger, and the water side outlet of the lean-rich liquid heat exchanger is connected to the regeneration tower. The rich liquid inlet is connected; the solution outlet of the regeneration tower is connected to the solution inlet of the reboiler; the solution outlet of the reboiler is connected to the hot phase inlet of the lean-rich liquid heat exchanger; the hot phase outlet of the lean-rich liquid heat exchanger is connected to the hot phase inlet of the lean liquid cooler, and the hot phase outlet of the lean liquid cooler is connected to the solution inlet of the absorption tower; the cold phase outlet of the lean liquid cooler is connected to the spray inlet of the pretreatment tower water; it is characterized in that: it also includes a flue gas heat exchanger and a heat pump system; the flue gas outlet of the dust collector is connected to the flue gas inlet of the flue gas heat exchanger, and the flue gas outlet of the flue gas heat exchanger is connected to the flue gas inlet of the desulfurization tower; the heat pump system is connected to the flue gas heat exchanger and the reboiler.

[0006] The utility model further comprises an induced draft fan, and the flue gas outlet of the flue gas heat exchanger is connected to the flue gas inlet of the desulfurization tower through the induced draft fan.

[0007] The utility model also comprises a chimney, the smoke outlet of the desulfurization tower is connected to the chimney, and the smoke outlet of the absorption tower is connected to the chimney.

[0008] The carbon dioxide capture device of the utility model further comprises a booster fan, and the flue gas outlet of the pretreatment tower is connected to the flue gas inlet of the absorption tower through the booster fan.

[0009] The solution outlet of the absorption tower of the utility model is connected with the water side inlet of the lean-rich liquid heat exchanger through a rich liquid pipeline, and a rich liquid pump is installed on the rich liquid pipeline.

[0010] The hot phase outlet of the lean liquid cooler of the utility model is connected with the solution inlet of the absorption tower through a lean liquid pump.

[0011] The heat pump system of the utility model comprises an evaporator, a compressor, a condenser and an expansion valve, and the evaporator, the compressor, the condenser and the expansion valve are connected in sequence.

[0012] The water side outlet of the flue gas heat exchanger of the utility model is connected with the hot phase inlet of the evaporator, and the water side inlet of the flue gas heat exchanger is connected with the hot phase outlet of the evaporator.

[0013] The water side inlet of the condenser of the utility model is connected with the condensate outlet of the reboiler, and the steam side outlet of the condenser is connected with the steam inlet of the reboiler.

[0014] The utility model also comprises a cold desalted water pipeline, which is divided into two paths, one of which is connected to the water side inlet of the flue gas heat exchanger, and the other is connected to the cold phase inlet of the lean liquid cooler.

[0015] Compared with the prior art, the utility model has the following advantages and effects:

[0016] (1) Compared with the traditional carbon dioxide capture system, the utility model utilizes the waste heat of the flue gas after the power plant dust collector and uses a high-temperature heat pump system to transfer the heat to generate low-pressure parameter steam, which is used as the regeneration steam for the reboiler of the carbon dioxide capture device. Only the new investment in the heat pump system and the flue gas heat exchanger is required, which saves a lot of operating costs;

[0017] (2) Use desalted water to cool the lean liquid for a second time to reduce the lean liquid temperature at the absorption tower inlet, thereby increasing the lean liquid carbon dioxide absorption efficiency and improving overall economic efficiency.

[0018] (3) In addition, the desalted water that has undergone heat exchange in the lean liquid cooler is sent to the pretreatment tower to cool and wash the flue gas, thereby realizing the full process utilization of the desalted water. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are provided to explain the present invention, but the present invention is not limited to the following examples.

[0021] The embodiment of the utility model includes a boiler 1, a dust collector 2, a flue gas heat exchanger 3, an induced draft fan 4, a desulfurization tower 5, a chimney 6, a carbon dioxide capture device, a heat pump system, a flue gas pipeline 101 before decarbonization, a flue gas pipeline 102 after decarbonization, a rich liquid pipeline 103, a solution connecting pipeline 104, a lean liquid pipeline 105, a cold desalted water pipeline 106, a hot desalted water pipeline 107, a steam pipeline 109 and a condensate pipeline 110; the carbon dioxide capture device includes a pretreatment tower 7, a booster fan 8, an absorption tower 9, a regeneration tower 10, a rich liquid pump 11, a lean-rich liquid heat exchanger 12, a lean liquid cooler 13, a lean liquid pump 14 and a reboiler 15.

[0022] The flue gas outlet of the boiler 1 is connected to the flue gas inlet of the dust collector 2, the flue gas outlet of the dust collector 2 is connected to the flue gas inlet of the flue gas heat exchanger 3, the flue gas outlet of the flue gas heat exchanger 3 is connected to the flue gas inlet of the desulfurization tower 5 through the induced draft fan 4, the flue gas outlet of the desulfurization tower 5 is connected to the chimney 6, and the flue gas of the boiler 1 is sent to the chimney 6 through the dust collector 2, the flue gas heat exchanger 3, the induced draft fan 4, and the desulfurization tower 5 in sequence.

[0023] The flue gas inlet of the pretreatment tower 7 is connected to the flue gas outlet of the desulfurization tower 5 through the flue gas duct 101 before decarbonization, and the flue gas duct 101 before decarbonization is drawn from the flue gas after the desulfurization tower 5; the flue gas outlet of the pretreatment tower 7 is connected to the flue gas inlet of the absorption tower 9 through the booster fan 8; the flue gas outlet of the absorption tower 9 is connected to the chimney 6 through the flue gas duct 102 after decarbonization.

[0024] The solution outlet of the absorption tower 9 is connected to the water side inlet of the lean-rich liquid heat exchanger 12 through the rich liquid pipeline 103. A rich liquid pump 11 is installed on the rich liquid pipeline 103. The water side outlet of the lean-rich liquid heat exchanger 12 is connected to the rich liquid inlet of the regeneration tower 10. The rich liquid of the absorption tower 9 is heated by the lean-rich liquid heat exchanger 12 and then sent to the regeneration tower 10.

[0025] The solution outlet of the regeneration tower 10 is connected to the solution inlet of the reboiler 15 through the solution connecting pipe 104; the solution outlet of the reboiler 15 is connected to the hot phase inlet of the lean-rich liquid heat exchanger 12 through the lean liquid pipe 105; the hot phase outlet of the lean-rich liquid heat exchanger 12 is connected to the hot phase inlet of the lean liquid cooler 13, and the hot phase outlet of the lean liquid cooler 13 is connected to the solution inlet of the absorption tower 9 through the lean liquid pump 14. The solution of the regeneration tower 10 enters the reboiler 15, is first cooled once by the lean-rich liquid heat exchanger 12, then cooled twice by the lean liquid cooler 13, and then pressurized by the lean liquid pump 14 to enter the absorption tower 9.

[0026] The heat pump system includes an evaporator 16, a compressor 17, a condenser 18 and an expansion valve 19, which are connected in sequence through a heat pump circulating medium pipeline 108 to realize a thermodynamic cycle. The heat pump system is connected to the flue gas heat exchanger 3, specifically, the water side outlet of the flue gas heat exchanger 3 is connected to the hot phase inlet of the evaporator 16 through a hot desalted water pipeline 107, and the water side inlet of the flue gas heat exchanger 3 is connected to the hot phase outlet of the evaporator 16. The heat pump system is also connected to the reboiler 15, specifically, the water side inlet of the condenser 18 is connected to the condensate outlet of the reboiler 15 through a condensate pipeline 110, and the steam side outlet of the condenser 18 is connected to the steam inlet of the reboiler 15 through a steam pipeline 109.

[0027] In this embodiment, the cold desalted water pipeline 106 is divided into two routes, one of which is connected to the water side inlet of the flue gas heat exchanger 3 to adjust the inlet water temperature; the other is connected to the cold phase inlet of the lean liquid cooler 13, and the cold phase outlet of the lean liquid cooler 13 is connected to the spray inlet of the pretreatment tower water 7.

[0028] The operation method of the utility model is as follows:

[0029] The system recovers waste heat from the flue gas heat exchanger 3 through the cold desalted water pipe 106, and exchanges the heat to the steam pipe 109 through the heat pump system; the steam is converted into condensed water after heat exchange in the reboiler 15, and enters the condenser 18 through the condensed water pipe 110 to realize a thermodynamic cycle; the system increases the secondary cooling of the lean liquid cooler 13 to cool the lean liquid to the optimal reaction temperature, thereby improving the system efficiency and reducing the amount of lean liquid circulation.

[0030] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the utility model. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the utility model are included in the protection scope of the utility model patent. Technicians in the technical field of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.

Claims

1. A waste heat utilization high temperature heat pump carbon dioxide capture system, comprising a boiler, a dust collector, a desulfurization tower and a carbon dioxide capture device, wherein the carbon dioxide capture device comprises a pretreatment tower, an absorption tower, a regeneration tower, a lean-rich liquid heat exchanger, a lean liquid cooler and a reboiler; the flue gas outlet of the boiler is connected to the flue gas inlet of the dust collector; the flue gas inlet of the pretreatment tower is connected to the flue gas outlet of the desulfurization tower, and the flue gas outlet of the pretreatment tower is connected to the flue gas inlet of the absorption tower; the solution outlet of the absorption tower is connected to the water side inlet of the lean-rich liquid heat exchanger, and the water side outlet of the lean-rich liquid heat exchanger is connected to the rich liquid inlet of the regeneration tower; the solution outlet of the regeneration tower is connected to the solution inlet of the reboiler; the solution outlet of the reboiler is connected to the hot phase inlet of the lean-rich liquid heat exchanger; the hot phase outlet of the lean-rich liquid heat exchanger is connected to the hot phase inlet of the lean liquid cooler, and the hot phase outlet of the lean liquid cooler is connected to the solution inlet of the absorption tower; the cold phase outlet of the lean liquid cooler is connected to the spray inlet of the pretreatment tower water; characterized in that: It also includes a flue gas heat exchanger and a heat pump system; the flue gas outlet of the dust collector is connected to the flue gas inlet of the flue gas heat exchanger, and the flue gas outlet of the flue gas heat exchanger is connected to the flue gas inlet of the desulfurization tower; the heat pump system is connected to the flue gas heat exchanger and the reboiler.

2. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 1 is characterized in that: It also includes an induced draft fan, and the flue gas outlet of the flue gas heat exchanger is connected to the flue gas inlet of the desulfurization tower through the induced draft fan.

3. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 1 is characterized in that: It also includes a chimney, the flue gas outlet of the desulfurization tower is connected to the chimney, and the flue gas outlet of the absorption tower is connected to the chimney.

4. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 1, characterized in that: The carbon dioxide capture device also includes a booster fan, and the flue gas outlet of the pretreatment tower is connected to the flue gas inlet of the absorption tower through the booster fan.

5. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 1, characterized in that: The solution outlet of the absorption tower is connected to the water side inlet of the lean-rich liquid heat exchanger through a rich liquid pipeline, and a rich liquid pump is installed on the rich liquid pipeline.

6. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 1, characterized in that: The hot phase outlet of the lean liquid cooler is connected to the solution inlet of the absorption tower through a lean liquid pump.

7. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 1, characterized in that: The heat pump system comprises an evaporator, a compressor, a condenser and an expansion valve, and the evaporator, the compressor, the condenser and the expansion valve are connected in sequence.

8. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 7, characterized in that: The water side outlet of the flue gas heat exchanger is connected to the hot phase inlet of the evaporator, and the water side inlet of the flue gas heat exchanger is connected to the hot phase outlet of the evaporator.

9. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 7, characterized in that: The water side inlet of the condenser is connected to the condensate outlet of the reboiler, and the steam side outlet of the condenser is connected to the steam inlet of the reboiler.

10. The waste heat utilization high temperature heat pump carbon dioxide capture system according to claim 1, characterized in that: It also includes a cold desalted water pipeline, which is divided into two routes, one route is connected to the water side inlet of the flue gas heat exchanger, and the other route is connected to the cold phase inlet of the lean liquid cooler.

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