Ammonia decarbonization cooling apparatus and method

Abstract

An ammonia decarbonization cooling apparatus and method. The cooling apparatus comprises: a first-stage cooling functional area (2-1), in which a process gas is cooled to a temperature Tgas1 by using a first circulation liquid; a second-stage cooling functional area (2-2), in which the process gas is cooled to a temperature Tgas2 by using a second circulation liquid; a third-stage cooling functional area (2-3), in which the process gas is cooled to a temperature Tgas3 by using a third circulation liquid, wherein Tgas3 < Tgas2 < Tgas1 < Tgas0, and Tgas0 represents the initial temperature of when the process gas enters the first-stage cooling functional area (2-1); a first cold source, which is used for cooling the first circulation liquid; a second cold source, which is used for cooling the second circulation liquid; and a third cold source, which is used for cooling the third circulation liquid, wherein the three cold sources are different from each other. In the apparatus and method, circulation water, a closed cooling tower or an air cooler, and a cold process gas, a refrigeration liquid or a refrigerating machine are used for staged cooling, and a low-energy-consumption cooling capacity and a recycled-process-gas cooling capacity are fully utilized, thereby saving on investment and reducing the energy consumption.

Description

Ammonia decarbonization cooling device and method Technical Field

[0001] The present invention belongs to the technical field of environmental protection, and in particular relates to a pre-cooling device and method for graded cooling process gas before ammonia decarbonization. Background Art

[0002] In recent years, the greenhouse effect has gradually become one of the most serious problems facing humanity. Carbon dioxide (CO2) is the most important greenhouse gas, and the use of fossil energy is its primary source of emissions. my country's total CO2 emissions already rank first in the world, and the coal-dominated energy structure in my country will continue for some time. Coal energy will remain the foundation of new energy peak regulation and energy security. my country has pledged to the world to reach peak carbon emissions by 2030 and achieve carbon neutrality by 2060. Capturing, storing, and utilizing CO2 in emissions as a resource is of great significance for controlling and reducing greenhouse gas emissions and addressing the greenhouse effect and global warming.

[0003] Currently, the predominant carbon capture technology used worldwide is the organic amine method, but it presents challenges such as high operating costs and high and difficult-to-treat emissions of waste gas, wastewater, and waste gas. Active exploration of new carbon removal technologies is ongoing both domestically and internationally. Compared to the organic amine method, the ammonia method offers advantages such as easy regeneration, low operating costs, and the production of the valuable ammonium bicarbonate fertilizer as a decarbonization byproduct. Ammonium bicarbonate is a typical compound fertilizer that simultaneously provides nitrogen fertilizer and CO2 to plants, making it particularly well-suited for modern soilless agriculture and greenhouse plant growth. This truly realizes the resource utilization of CO2, enabling carbon recycling and avoiding potential secondary pollution and CO2 environmental accidents caused by underground carbon storage. Compared to organic amine decarbonization, ammonia absorbs CO2 more efficiently, and the resulting ammonium bicarbonate is more easily regenerated, significantly reducing decarbonization costs.

[0004] Ammonia-based decarbonization technology has long been a research focus and the best approach to addressing greenhouse gas emissions. However, ammonia is volatile, leading to increased ammonia escape. If unaddressed, this large amount of ammonia escape not only increases decarbonization costs but also causes secondary pollution. Lowering the decarbonization temperature can be used to reduce ammonia escape.

[0005] Patent CN201210410873.0 discloses a multi-stage cooling tower system, which includes multiple cooling towers. The outlet water of the previous cooling tower is used as the inlet water of the next cooling tower, performing multi-stage cooling. This system only uses multiple cooling towers for the same cooling gradient to improve cooling efficiency, using the same cooling source.

[0006] Patent CN200880122376.2 discloses a multi-stage CO2 removal system and method for treating flue gas streams. The system uses an absorber vessel to contact the flue gas stream with an ionic solution containing ammonia at a low temperature of 0-20°C. The solution in the first absorption stage has a higher temperature and a lower ammonia-to-carbon ratio than the solution in the third absorption stage. By controlling the ionic solution at a lower temperature, and also keeping the ionic solution in the third stage at an even lower temperature, ammonia slip can be reduced. However, the patent does not address how to achieve efficient and energy-efficient cooling.

[0007] The present invention aims to provide a multi-stage cooling device and method for wet ammonia decarbonization. The device uses different cooling sources to cool the desulfurized gas in stages in a cooling tower, thereby saving investment and reducing energy consumption.

[0008] Summary of the Invention

[0009] The present invention achieves the above-mentioned purpose through the following technical solutions.

[0010] In the first aspect, the present invention provides a pre-cooling device before ammonia decarbonization, which comprises: a first stage cooling functional zone, which uses a first circulating liquid to cool the process gas to a temperature T 气1 The second cooling zone uses the second circulating liquid to cool the process gas to a temperature of T 气2 The third cooling zone uses the third circulating liquid to cool the process gas to a temperature of T 气3 , where T 气3 <T 气2 <T 气1 <T 气0 , where T 气0 It is the initial temperature of the process gas when it enters the first-stage cooling functional area; the first cold source is used to cool the first circulating liquid, the second cold source is used to cool the second circulating liquid, and the third cold source is used to cool the third circulating liquid, wherein the three cold sources are different.

[0011] In a second aspect, the present invention provides a method for cooling a process gas, comprising passing the process gas sequentially through: a first stage cooling functional zone, which uses a first circulating liquid to cool the process gas to a temperature T 气1 The second cooling zone uses the second circulating liquid to cool the process gas to a temperature of T 气2 The third cooling zone uses the third circulating liquid to cool the process gas to a temperature of T 气3 , where T 气3 <T 气2 <T 气1 <T 气0 , where T 气0It is the initial temperature of the process gas when it enters the first-stage cooling functional area; the first cooling source is used to cool the first circulating liquid, the second cooling source is used to cool the second circulating liquid, and the third cooling source is used to cool the third circulating liquid, wherein the three cooling sources are different.

[0012] Preferably, the first cooling source is cooling water from a circulating cooling water source or a closed cooling tower, which cools the first circulating liquid through a first heat exchanger; alternatively, the first cooling source is air, which directly cools the first circulating liquid through an air cooler. Preferably, the second cooling source is cold process gas after decarburization, which indirectly cools the second circulating liquid through a second heat exchanger, or directly cools the second circulating liquid through cross-spraying of spray liquid. Preferably, the third cooling source is a chilled liquid, preferably obtained from a refrigerator, which cools the third circulating liquid through a third heat exchanger, or directly cools the third circulating liquid through the refrigerator's cooling source.

[0013] The cooling device and method of the present invention utilize circulating cooling water, closed-circuit cooling tower cooling water, air from an air cooler, cold process gas, and refrigerant as cooling sources. The circulating liquid spray cools the process gas, fully utilizing low-energy cooling capacity and recycling process gas cooling capacity, thereby saving investment and reducing energy consumption. Furthermore, the cooling device and method of the present invention can reduce the temperature of the process gas to a relatively low level, for example, 10-30°C, thereby significantly reducing ammonia slip during the subsequent decarbonization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG1 shows the pre-cooling device before ammonia decarbonization in Example 1.

[0015] FIG2 shows the pre-cooling device before ammonia decarbonization in Example 2.

[0016] FIG3 shows a pre-cooling device before ammonia decarbonization of a comparative example.

[0017] In the drawings, the symbols have the following meanings:

[0018] Process gas 1, decarbonization cooling tower 2, cooling tower first-stage cooling zone 2-1, cooling tower second-stage cooling zone 2-2, cooling tower third-stage cooling zone 2-3, cooling tower first-stage cooling zone circulation pump 3-1, cooling tower second-stage cooling zone circulation pump 3-2, cooling tower third-stage cooling zone circulation pump 3-3, cooling tower first-stage cooling zone heat exchanger 4-1, cooling tower second-stage cooling zone heat exchanger 4-2, cooling tower third-stage cooling zone heat exchanger 4-3, air cooler 4-4, circulating cooling water 5-1, chilled water 5-2, cooling tower process gas output pipeline 6, decarbonization absorption tower 7, decarbonization absorption tower circulation pump 8, decarbonization absorption tower process gas output pipeline 9, ammonia escape control system water washing zone circulation pump 10, process gas discharge 11, ammonia escape control system 12.

[0019] Detailed Description of the Preferred Embodiments

[0020] In the first aspect, the present invention provides a pre-cooling device before ammonia decarbonization, which comprises: a first stage cooling functional zone, which uses a first circulating liquid to cool the process gas to a temperature T 气1 The second cooling zone uses the second circulating liquid to cool the process gas to a temperature of T 气2 The third cooling zone uses the third circulating liquid to cool the process gas to a temperature of T 气3 , where T 气3 <T 气2 <T 气1 <T 气0 , where T 气0 It is the initial temperature of the process gas when it enters the first-stage cooling functional area; the first cold source is used to cool the first circulating liquid, the second cold source is used to cool the second circulating liquid, and the third cold source is used to cool the third circulating liquid, wherein the three cold sources are different.

[0021] In one embodiment, the first cooling source is cooling water from a circulating cooling water or a closed cooling tower, and the first circulating liquid is cooled by the first heat exchanger.

[0022] In one embodiment, the first cooling source is air, which directly cools the first circulating liquid through an air cooler.

[0023] In one embodiment, the second cold source is the cold process gas after decarburization, which is cooled by indirect heat exchange through a second heat exchanger or by direct heat exchange through cross spraying of spray liquid.

[0024] In one embodiment, the third cold source is a refrigerated liquid, and the refrigerated liquid is preferably obtained by a refrigerator, and the third circulating liquid is cooled by a third heat exchanger, or the third circulating liquid is directly cooled by a refrigerator cold source.

[0025] The first heat exchanger and the third heat exchanger are liquid-liquid heat exchangers, preferably plate heat exchangers. The second heat exchanger is a gas-liquid heat exchanger, preferably a shell and tube heat exchanger.

[0026] In one embodiment, devices or components that only allow gas to pass through are provided between the cooling functional areas.

[0027] In one embodiment, at least one layer of circulation distributor is provided in each cooling functional zone.

[0028] The circulation distributor can be a trough distributor or a spray distributor.

[0029] In one embodiment, the three functional zones may be combined into one column or exist as multiple columns.

[0030] When the three functional areas are combined into a tower, namely a cooling tower, the cooling device of the present invention includes a cooling tower and a cold source, and the cooling tower includes a first-level cooling functional area, a second-level cooling functional area and a third-level cooling functional area from bottom to top, wherein the various cooling functional areas and cold sources are as described herein.

[0031] In one embodiment, T 气0 40-80°C; and / or T 气1 35-48°C; and / or T 气2 15-40°C; and / or T 气3 10-30℃.

[0032] In one embodiment, the inlet temperature of the first circulating liquid is T 液1 , the tower temperature is T 液1’ , where T 液 1 <T 液1’ , T 气0 -T 液1’ =ΔT1; the inlet temperature of the second circulating liquid is T 液2 , the tower temperature is T 液2’ , where T 液2 <T 液2’ , T 气1 -T 液2’ =ΔT2; and the inlet temperature of the third circulating liquid is T 液3 , the tower temperature is T 液3’ , where T 液3 <T 液3’ , T 气2 -T 液3’ =ΔT3; wherein ΔT1, ΔT2, and ΔT3 are each independently ≥1°C, preferably 2-15°C, and more preferably 2-5°C.

[0033] In one embodiment, T 液1 10-40℃, T 液1’ 15-50°C; and / or T 液2 15-36℃, T 液2’ 20-45°C; and / or T 液3 0-25℃, T 液3’ 10-40℃.

[0034] In one embodiment, the temperature of the first cold source before heat exchange is T 源1 , the temperature after heat exchange is T 源1’ , where T 源1 <T 源1’ ; The temperature of the second cold source before heat exchange is T 源2 , the temperature after heat exchange is T 源2’ , where T 源2 <T源2’ ; The temperature before heat exchange with the third cold source is T 源3 , the temperature after heat exchange is T 源3’ , where T 源3 <T 源3’ .

[0035] In one embodiment, T 源1 5-35℃, T 源1’ 10-45°C; and / or T 源2 10-30℃, T 源2’ 15-40°C; and / or T 源3 -17 to 10°C, T 源3’ 0-30℃.

[0036] In one embodiment, the cooling device is part of an ammonia desulfurization and decarbonization system, the upstream of the cooling device is connected to the desulfurization device, the downstream of the cooling device is connected to the decarbonization device, and the process gas comes from the desulfurization device, is cooled by the cooling device, and then enters the decarbonization device.

[0037] Preferably, the process gas is desulfurized process gas from a desulfurization device, and its temperature is generally 40-80° C., preferably 40-60° C. The desulfurization process removes most of the SO 2 in the process gas, so that the desulfurized process gas mainly contains CO 2 and a small amount of H 2 O.

[0038] In a second aspect, the present invention provides a method for cooling a process gas, comprising passing the process gas sequentially through: a first stage cooling functional zone, which uses a first circulating liquid to cool the process gas to a temperature T 气1 The second cooling zone uses the second circulating liquid to cool the process gas to a temperature of T 气2 The third cooling zone uses the third circulating liquid to cool the process gas to a temperature of T 气3 , where T 气3 <T 气2 <T 气1 <T 气0 , where T 气0 It is the initial temperature of the process gas when it enters the first-stage cooling functional area; the first cooling source is used to cool the first circulating liquid, the second cooling source is used to cool the second circulating liquid, and the third cooling source is used to cool the third circulating liquid, wherein the three cooling sources are different.

[0039] In one embodiment, the first cooling source is cooling water from a circulating cooling water or a closed cooling tower, and the first circulating liquid is cooled by the first heat exchanger.

[0040] In one embodiment, the first cooling source is air, which directly cools the first circulating liquid through an air cooler.

[0041] In one embodiment, the second cold source is the cold process gas after decarburization, which is cooled by indirect heat exchange through a second heat exchanger or by direct heat exchange through cross spraying of spray liquid.

[0042] In one embodiment, the third cold source is a refrigerated liquid, and the refrigerated liquid is preferably obtained by a refrigerator, and the third circulating liquid is cooled by a third heat exchanger, or the third circulating liquid is directly cooled by a refrigerator cold source.

[0043] In one embodiment, T 气0 40-80°C; and / or T 气1 35-48°C; and / or T 气2 15-40°C; and / or T 气3 10-30℃.

[0044] In one embodiment, the inlet temperature of the first circulating liquid is T 液1 , the tower temperature is T 液1’ , where T 液 1 <T 液1’ , T 气0 -T 液1’ =ΔT1; the inlet temperature of the second circulating liquid is T 液2 , the tower temperature is T 液2’ , where T 液2 <T 液2’ , T 气1 -T 液2’ =ΔT2; and the inlet temperature of the third circulating liquid is T 液3 , the tower temperature is T 液3’ , where T 液3 <T 液3’ , T 气2 -T 液3’ =ΔT3; wherein ΔT1, ΔT2, and ΔT3 are each independently ≥1°C, preferably 2-15°C, and more preferably 2-5°C.

[0045] In one embodiment, T 液1 10-40℃, T 液1’ 15-50°C; and / or T 液2 15-36℃, T 液2’ 20-45°C; and / or T 液3 0-25℃, T 液3’ 10-40℃.

[0046] In one embodiment, the temperature of the first cold source before heat exchange is T 源1 , the temperature after heat exchange is T 源1’ , where T 源1 <T 源1’ ; The temperature of the second cold source before heat exchange is T源2 , the temperature after heat exchange is T 源2’ , where T 源2 <T 源2’ ; The temperature before heat exchange with the third cold source is T 源3 , the temperature after heat exchange is T 源3’ , where T 源3 <T 源3’ .

[0047] In one embodiment, T 源1 5-35℃, T 源1’ 10-45°C; and / or T 源2 10-30℃, T 源2’ 15-40°C; and / or T 源3 -17 to 10°C, T 源3’ 0-30℃.

[0048] In one embodiment, the method is part of an ammonia desulfurization and decarbonization method, the upstream of the cooling method is a desulfurization process, the downstream of the cooling method is a decarbonization process, and the process gas comes from the desulfurization process and enters the decarbonization process after being cooled by the cooling method.

[0049] In the apparatus and method of the present invention, the circulating liquid may be water. During the circulation process, components entrained by the process gas may enter the circulating liquid, causing the circulating liquid to contain components such as ammonium sulfate.

[0050] In one embodiment, the ammonium sulfate content in the cooling circulating fluid is 0-5%, and the first stage > the second stage > the third stage.

[0051] Preferably, the method of cooling a process gas according to the present invention is performed by a cooling device as described herein. Preferably, the cooling device according to the present invention is a device for performing the method of cooling a process gas according to the present invention. Various features described herein for the cooling device also apply to the method, and vice versa. DETAILED DESCRIPTION

[0052] The following examples are provided to illustrate the present invention, not to limit the scope of the invention.

[0053] Example 1 is a cooling device of the present invention, shown in Figure 1. Example 2 is a cooling device of the present invention, shown in Figure 2. The comparative example is shown in Figure 3. The difference between Figure 1 and Figure 2 mainly lies in the cold source and cooling method. The first and second stage cooling of Figure 1 are respectively: circulating cooling water 5-1 cools the circulating liquid through heat exchanger 4-1, and cold process gas 9 cools the circulating liquid through heat exchanger 4-2. The first and second stage cooling of Figure 2 are respectively: cooling the circulating liquid through air cooler 4-4, and cooling the circulating liquid through spray contact with cold process gas 9. The cooling tower of Figure 3 cools the circulating liquid only through chilled water 5-2 through heat exchanger 4-3.

[0054] Example 1

[0055] As shown in Figure 1, the process gas 1 (893837Nm 3 / h, 50°C) enters the first cooling zone 2-1 of decarbonization cooling tower 2. The circulating liquid is pumped into the cooling tower by the first cooling zone circulating pump 3-1 for spraying, where it comes into contact with the process gas, cooling it to 42°C. A heat exchanger 4-1 is installed on the circulating liquid pipeline, where the circulating liquid is cooled by circulating cooling water 5-1. The circulating liquid enters the tower at a temperature of 38°C and exits at a temperature of 48°C. The circulating cooling water enters the heat exchanger at a temperature of 30°C and exits at a temperature of 40°C.

[0056] After the first stage of cooling, the process gas passes through the liquid collector and enters the second stage cooling zone 2-2. Spraying is used to cool the process gas to 39°C. The circulating liquid exchanges heat with the decarburized process gas in the degassing heat exchanger 4-2, then returns to the second stage cooling zone 2-2 to cool the process gas. The circulating liquid inlet temperature is 30°C, and the outlet temperature is 40°C. The decarburized process gas temperature rises from 20°C to 31°C.

[0057] After the second stage of cooling, the process gas passes through the liquid collector and enters the third stage cooling zone 2-3. The circulating fluid passes through heat exchanger 4-3, where it is cooled by chilled water 5-2. The circulating fluid is then sprayed into the tower, cooling the process gas to 25°C. The circulating fluid enters the tower at 20°C and exits at 37°C. The chilled water enters heat exchanger 4-3 at 7°C and exits at 17°C.

[0058] After cooling in the cooling tower, the process gas is output to the decarbonization tower 7 via flue 6. Circulating fluid, passing through a circulating pump 8, comes into contact with the process gas to absorb carbon dioxide. The decarbonized process gas enters the ammonia escape control system 12 through flue 9, which is equipped with a gas heat exchanger 4-2. The circulating fluid in the ammonia escape control system is scrubbed by a circulating pump 10 and comes into contact with the process gas to absorb free ammonia. The deammonified process gas 11 is then discharged through the process gas discharge outlet.

[0059] The circulating cooling water consumption is 1890t / h and the chilled water consumption is 1894t / h.

[0060] The main process parameters of the cooling treatment in Example 1 are shown in Table 1.

[0061] Table 1. Main process parameters of cooling treatment in Example 1

[0062] Example 2

[0063] As shown in Figure 2, the process gas 1 (893837Nm 3 / h, 50°C) enters the first cooling zone 2-1 of decarbonization cooling tower 2. The circulating fluid is pumped into the cooling tower by the first cooling zone circulating pump 3-1 for spraying, where it comes into contact with the process gas, cooling it to 42°C. An air cooler 4-4 is installed on the circulating fluid pipeline, directly cooling the circulating fluid. The circulating fluid enters the tower at a temperature of 38°C and leaves the tower at a temperature of 48°C.

[0064] After the first stage of cooling, the process gas passes through the liquid collector and enters the second stage cooling zone 2-2. Spraying is used to cool the process gas to 32°C. The circulating liquid, through the ammonia escape control system 12, is sprayed with the decarburized process gas for heat exchange and cooling. The circulating liquid then returns to the second stage cooling zone 2-2 to cool the process gas. The circulating liquid enters the cooling tower at 25°C and exits at 40°C. The decarburized process gas temperature rises from 20°C to 35°C.

[0065] After the second stage of cooling, the process gas passes through the liquid collector and enters the third stage cooling zone 2-3. It then passes through heat exchanger 4-3, where the circulating fluid is cooled by chilled water 5-2. The circulating fluid is then sprayed into the tower, cooling the process gas to 25°C. The circulating fluid enters the tower at 20°C and exits at 30°C. The chilled water enters heat exchanger 4-3 at 7°C and exits at 17°C.

[0066] After cooling in the cooling tower, the process gas is output to the decarbonization tower 7 via flue 6. Circulating fluid, passing through a circulating pump 8, comes into contact with the process gas to absorb carbon dioxide. The decarbonized process gas passes through flue 9 and enters the ammonia escape control system 12. The circulating fluid in the ammonia escape control system is scrubbed by a circulating pump 10 and comes into contact with the process gas to absorb free ammonia. The deammonified process gas 11 is discharged through the process gas discharge outlet.

[0067] Chilled water consumption is 818t / h.

[0068] The main process parameters of the cooling treatment in Example 2 are shown in Table 2.

[0069] Table 2. Main process parameters of cooling treatment in Example 2

[0070] Comparative Example

[0071] As shown in Figure 3, the process gas after ammonia desulfurization 1 (893837Nm 3 / h, 50°C) enters decarbonization cooling tower 2. The circulating fluid passes through heat exchanger 4-3, where it is cooled by chilled water 5-2. The circulating fluid is then sprayed into the tower, cooling the process gas to 25°C. The circulating fluid enters the tower at 20°C and exits at 48°C. The chilled water enters heat exchanger 4-3 at 7°C and exits at 17°C.

[0072] Chilled water consumption is 4267t / h.

[0073] The main process parameters of the cooling treatment in the comparative example are shown in Table 3.

[0074] Table 3. Main process parameters of cooling treatment in comparative example

[0075] The present invention also relates to the following embodiments:

[0076] 1. A pre-cooling device before ammonia decarbonization, comprising:

[0077] The first stage cooling function area uses the first circulating liquid to cool the process gas to the temperature T 气1 ,

[0078] The second cooling zone uses the second circulating fluid to cool the process gas to a temperature of T 气2 ,

[0079] The third cooling zone uses the third circulating fluid to cool the process gas to a temperature of T 气3 ,

[0080] Where T 气3 <T 气2 <T 气1 <T 气0 , where T 气0 is the initial temperature of the process gas when it enters the first stage cooling functional zone; preferably, T 气0 40-80°C; and / or T 气1 35-48°C; and / or T 气2 15-40°C; and / or T 气3 10-30℃;

[0081] The first cooling source is used to cool the first circulating fluid.

[0082] The second cold source is used to cool the second circulating fluid,

[0083] The third cooling source is used to cool the third circulating fluid.

[0084] The three cooling sources are different.

[0085] 2. The pre-cooling device according to embodiment 1, wherein the first cooling source is cooling water from circulating cooling water or a closed cooling tower, and the first circulating liquid is cooled by the first heat exchanger, or the first cooling source is air, and the first circulating liquid is directly cooled by an air cooler; and / or

[0086] The second cooling source is the cold process gas after decarburization, which is cooled by indirect heat exchange through the second heat exchanger or directly cooled by cross-spraying of the spray liquid; and / or

[0087] The third cold source is a freezing liquid, and preferably the freezing liquid is obtained by a refrigerator, and the third circulating liquid is cooled by a third heat exchanger, or the third circulating liquid is directly cooled by a refrigerator cold source.

[0088] 3. The pre-cooling device according to embodiment 1 or 2, wherein a device or component that only allows gas to pass is provided between each cooling functional area; and / or

[0089] Each cooling functional area is provided with at least one layer of liquid distributor, and the liquid distributor may be a trough distributor or a spray distributor; and / or

[0090] The three functional areas may be combined into one tower or exist as multiple towers; and / or

[0091] The cooling device is part of the ammonia desulfurization and decarbonization system. The upstream of the cooling device is connected to the desulfurization device, and the downstream of the cooling device is connected to the decarbonization device. The process gas comes from the desulfurization device, is cooled by the cooling device, and then enters the decarbonization device.

[0092] 4. The pre-cooling device according to any one of embodiments 1-3, wherein:

[0093] The inlet temperature of the first circulating liquid is T 液1 , the tower temperature is T 液1’ , where T 液1 <T 液1’ , T 气0 -T 液1’ =ΔT1; preferably, T 液1 10-40℃, T 液1’ 15-50℃;

[0094] The inlet temperature of the second circulating liquid is T 液2 , the tower temperature is T 液2’ , where T 液2 <T 液2’ , T 气1 -T 液2’ =ΔT2; preferably, T 液2 15-36℃, T 液2’ 20-45°C; and

[0095] The inlet temperature of the third circulating liquid is T 液3 , the tower temperature is T 液3’ , where T 液3 <T 液3’ , T 气2 -T 液3’ =ΔT3; preferably, T 液3 0-25℃, T 液3’ 10-40℃;

[0096] wherein ΔT1, ΔT2, and ΔT3 are each independently ≥1°C, preferably 2-15°C, and more preferably 2-5°C.

[0097] 5. The pre-cooling device according to any one of embodiments 1-4, wherein:

[0098] The temperature of the first cold source before heat exchange is T 源1 , the temperature after heat exchange is T 源1’ , where T 源1 <T 源1’ ; Preferably, T 源1 5-35℃, T 源1’ 10-45℃;

[0099] The temperature of the second cold source before heat exchange is T 源2 , the temperature after heat exchange is T 源2’ , where T 源2 <T 源2’ ; Preferably, T 源2 10-30℃, T 源2’ 15-40°C; and

[0100] The temperature of the third cold source before heat exchange is T 源3 , the temperature after heat exchange is T 源3’ , where T 源3 <T 源3’ ; Preferably, T 源3 -17 to 10°C, T 源3’ 0-30℃.

[0101] 6. A method of cooling a process gas, comprising passing the process gas sequentially through:

[0102] The first stage cooling function area uses the first circulating liquid to cool the process gas to the temperature T 气1 ,

[0103] The second cooling zone uses the second circulating fluid to cool the process gas to a temperature of T 气2 ,

[0104] The third cooling zone uses the third circulating fluid to cool the process gas to a temperature of T 气3 ,

[0105] Where T 气3 <T 气2 <T 气1 <T 气0 , where T 气0 is the initial temperature of the process gas when it enters the first stage cooling functional zone; preferably, T 气0 40-80°C; and / or T 气1 35-48°C; and / or T 气2 15-40°C; and / or T 气3 10-30℃;

[0106] Use the first cold source to cool the first circulating fluid,

[0107] Use the second cold source to cool the second circulating fluid,

[0108] Use the third cold source to cool the third circulating fluid,

[0109] The three cooling sources are different.

[0110] 7. The method according to embodiment 6, wherein the first cooling source is cooling water from circulating cooling water or a closed cooling tower, and the first circulating liquid is cooled by the first heat exchanger, or the first cooling source is air, and the first circulating liquid is directly cooled by an air cooler; and / or

[0111] The second cooling source is the cold process gas after decarburization, which is cooled by indirect heat exchange through the second heat exchanger or directly cooled by cross-spraying of the spray liquid; and / or

[0112] The third cold source is a freezing liquid, and preferably the freezing liquid is obtained by a refrigerator, and the third circulating liquid is cooled by a third heat exchanger, or the third circulating liquid is directly cooled by a refrigerator cold source.

[0113] 8. The method according to embodiment 6 or 7, wherein:

[0114] The inlet temperature of the first circulating liquid is T 液1 , the tower temperature is T 液1’ , where T 液1 <T 液1’ , T 气0 -T 液1’ =ΔT1; preferably, T 液1 10-40℃, T 液1’ 15-50℃;

[0115] The inlet temperature of the second circulating liquid is T 液2 , the tower temperature is T液2’ , where T 液2 <T 液2’ , T 气1 -T 液2’ =ΔT2; preferably, T 液2 15-36℃, T 液2’ 20-45°C; and

[0116] The inlet temperature of the third circulating liquid is T 液3 , the tower temperature is T 液3’ , where T 液3 <T 液3’ , T 气2 -T 液3’ =ΔT3; preferably, T 液3 0-25℃, T 液3’ 10-40℃;

[0117] wherein ΔT1, ΔT2, and ΔT3 are each independently ≥1°C, preferably 2-15°C, and more preferably 2-5°C.

[0118] 9. The method according to any one of embodiments 6-8, wherein:

[0119] The temperature of the first cold source before heat exchange is T 源1 , the temperature after heat exchange is T 源1’ , where T 源1 <T 源1’ ; Preferably, T 源1 5-35℃, T 源1’ 10-45℃;

[0120] The temperature of the second cold source before heat exchange is T 源2 , the temperature after heat exchange is T 源2’ , where T 源2 <T 源2’ ; Preferably, T 源2 10-30℃, T 源2’ 15-40°C; and

[0121] The temperature of the third cold source before heat exchange is T 源3 , the temperature after heat exchange is T 源3’ , where T 源3 <T 源3’ ; Preferably, T 源3 -17 to 10°C, T 源3’ 0-30℃.

[0122] 10. The method according to any one of embodiments 6-9, wherein the method is part of an ammonia desulfurization and decarbonization method, the upstream of the cooling method is a desulfurization process, the downstream of the cooling method is a decarbonization process, the process gas comes from the desulfurization process, is cooled by the cooling method, and then enters the decarbonization process; and / or

[0123] The ammonium sulfate content in the cooling circulating fluid is 0-5%, and the first level>the second level>the third level.

[0124] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that these are merely examples and that the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications fall within the scope of protection of the present invention. Furthermore, it should be understood by those skilled in the art that the technical features described herein for one or more embodiments may be combined with other embodiments, as long as such combination does not conflict with the purpose of the present invention.

Claims

1. A pre-cooling device before ammonia decarbonization, comprising: The first stage cooling function area uses the first circulating liquid to cool the process gas to the temperature T 气1 , The second cooling zone uses the second circulating fluid to cool the process gas to a temperature of T 气2 , The third cooling zone uses the third circulating fluid to cool the process gas to a temperature of T 气3 , Where T 气3 <T 气2 <T 气1 <T 气0 , where T 气0 It is the initial temperature of the process gas when it enters the first stage cooling functional area; The first cooling source is used to cool the first circulating fluid. The second cold source is used to cool the second circulating fluid, The third cooling source is used to cool the third circulating fluid. The three cooling sources are different.

2. The pre-cooling device according to claim 1, wherein the first cold source is cooling water from circulating cooling water or a closed cooling tower, and the first circulating liquid is cooled by the first heat exchanger.

3. The pre-cooling device according to claim 1, wherein the first cooling source is air, and the first circulating liquid is directly cooled by an air cooler.

4. The pre-cooling device according to claim 1, wherein the second cold source is the cold process gas after decarburization, and the second circulating liquid is cooled by indirect heat exchange through the second heat exchanger, or directly cooled by heat exchange through cross spraying of spray liquid.

5. The pre-cooling device according to claim 1, wherein the third cold source is a refrigerant, preferably the refrigerant is obtained by a refrigerator, and the third circulating liquid is cooled by a third heat exchanger, or the third circulating liquid is directly cooled by the refrigerator cold source.

6. The pre-cooling device according to any one of claims 1 to 5, wherein equipment or components that only allow gas to pass through are provided between each cooling functional area.

7. The pre-cooling device according to any one of claims 1 to 6, wherein each cooling functional area is provided with at least one layer of liquid distributor, and the liquid distributor can be a trough distributor or a spray distributor.

8. The pre-cooling device according to any one of claims 1 to 7, wherein the three functional zones can be combined into one tower or exist as multiple towers.

9. The pre-cooling device according to any one of claims 1 to 8, wherein: T 气0 40-80°C; and / or T 气1 35-48°C; and / or T 气2 15-40°C; and / or T 气3 10-30℃.

10. The pre-cooling device according to any one of claims 1 to 9, wherein: The inlet temperature of the first circulating liquid is T 液1 , the tower temperature is T 液1’ , where T 液1 <T 液1’ , T 气0 -T 液1’ =ΔT1; The inlet temperature of the second circulating liquid is T 液2 , the tower temperature is T 液2’ , where T 液2 <T 液2’ , T 气1 -T 液2’ =ΔT2; and The inlet temperature of the third circulating liquid is T 液3 , the tower temperature is T 液3’ , where T 液3 <T 液3’ , T 气2 -T 液3’ =ΔT3; wherein ΔT1, ΔT2, and ΔT3 are each independently ≥1°C, preferably 2-15°C, and more preferably 2-5°C.

11. The pre-cooling device according to claim 10, wherein: T 液1 10-40℃, T 液1’ 15-50°C; and / or T 液2 15-36℃, T 液2’ 20-45°C; and / or T 液3 0-25℃, T 液3’ 10-40℃.

12. The pre-cooling device according to any one of claims 1 to 11, wherein: The temperature of the first cold source before heat exchange is T 源1 , the temperature after heat exchange is T 源1’ , where T 源1 <T 源1’ ; The temperature of the second cold source before heat exchange is T 源2 , the temperature after heat exchange is T 源2’ , where T 源2 <T 源2’ ;and The temperature of the third cold source before heat exchange is T 源3 , the temperature after heat exchange is T 源3’ , where T 源3 <T 源3’ .

13. The pre-cooling device according to claim 12, wherein: T 源1 5-35℃, T 源1’ 10-45°C; and / or T 源2 10-30℃, T 源2’ 15-40°C; and / or T 源3 -17 to 10°C, T 源3’ 0-30℃.

14. A pre-cooling device according to any one of claims 1 to 13, wherein the cooling device is part of an ammonia desulfurization and decarbonization system, the upstream of the cooling device is connected to a desulfurization device, the downstream of the cooling device is connected to a decarbonization device, and the process gas comes from the desulfurization device, is cooled by the cooling device, and then enters the decarbonization device.

15. A method of cooling a process gas, comprising passing the process gas sequentially through: The first stage cooling function area uses the first circulating liquid to cool the process gas to the temperature T 气1 , The second cooling zone uses the second circulating fluid to cool the process gas to a temperature of T 气2 , The third cooling zone uses the third circulating fluid to cool the process gas to a temperature of T 气3 , Where T 气3 <T 气2 <T 气1 <T 气0 , where T 气0 It is the initial temperature of the process gas when it enters the first stage cooling functional area; Use the first cold source to cool the first circulating fluid, Use the second cold source to cool the second circulating fluid, Use the third cold source to cool the third circulating fluid, The three cooling sources are different.

16. The method according to claim 15, wherein the first cold source is cooling water from circulating cooling water or a closed cooling tower, and the first circulating liquid is cooled by the first heat exchanger.

17. The method according to claim 15, wherein the first cooling source is air, and the first circulating liquid is directly cooled by an air cooler.

18. The method according to claim 15, The second cold source is the cold process gas after decarburization, which is cooled by indirect heat exchange through the second heat exchanger or directly cooled by cross-spraying of the spray liquid.

19. The method according to claim 15, The third cold source is a refrigerated liquid, preferably obtained by a refrigerator, and cooled by a third heat exchanger. The third circulating fluid can be directly cooled by a cold source of a refrigerator.

20. The method according to any one of claims 15 to 19, wherein: T 气0 40-80°C; and / or T 气1 35-48°C; and / or T 气2 15-40°C; and / or T 气3 10-30℃.

21. The method according to any one of claims 15 to 20, wherein: The inlet temperature of the first circulating liquid is T 液1 , the tower temperature is T 液1’ , where T 液1 <T 液1’ , T 气0 -T 液1’ =ΔT1; The inlet temperature of the second circulating liquid is T 液2 , the tower temperature is T 液2’ , where T 液2 <T 液2’ , T 气1 -T 液2’ =ΔT2; and The inlet temperature of the third circulating liquid is T 液3 , the tower temperature is T 液3’ , where T 液3 <T 液3’ , T 气2 -T 液3’ =ΔT3; wherein ΔT1, ΔT2, and ΔT3 are each independently ≥1°C, preferably 2-15°C, and more preferably 2-5°C.

22. The method of claim 21, wherein: T 液1 10-40℃, T 液1’ 15-50°C; and / or T 液2 15-36℃, T 液2’ 20-45°C; and / or T 液3 0-25℃, T 液3’ 10-40℃.

23. The method according to any one of claims 15 to 22, wherein: The temperature of the first cold source before heat exchange is T 源1 , the temperature after heat exchange is T 源1’ , where T 源1 <T 源1’ ; The temperature of the second cold source before heat exchange is T 源2 , the temperature after heat exchange is T 源2’ , where T 源2 <T 源2’ ;and The temperature of the third cold source before heat exchange is T 源3 , the temperature after heat exchange is T 源3’ , where T 源3 <T 源3’ .

24. The method of claim 23, wherein: T 源1 5-35℃, T 源1’ 10-45°C; and / or T 源2 10-30℃, T 源2’ 15-40°C; and / or T 源3 -17 to 10°C, T 源3’ 0-30℃.

25. The method according to any one of claims 15-24, wherein the method is part of an ammonia desulfurization and decarbonization method, the upstream of the cooling method is a desulfurization process, the downstream of the cooling method is a decarbonization process, and the process gas comes from the desulfurization process and enters the decarbonization process after being cooled by the cooling method.

26. The method according to any one of claims 15 to 24, wherein the ammonium sulfate content in the cooling circulating fluid is 0-5%, and the first stage > the second stage > the third stage.