Pre-cooling system based on air separation device

Abstract

The utility model relates to the technical field of air separation devices, in particular to a pre-cooling system based on an air separation device, which comprises a circulating water tank, a water inlet pipe, a water outlet pipe and a water outlet pipe, the air cooling tower is connected with the circulating water tank through a circulating pipe; the refrigeration equipment is connected with the air cooling tower through a freezing pipe; one end of the water replenishing system is connected with an external water source of the pre-cooling system, and the other end is connected with the refrigeration equipment; according to the utility model, the make-up water is directly conveyed to the water cooling tower through the water replenishing system, the make-up water is cooled by the water cooling tower, and because the ion concentration of the make-up water is lower, the make-up water cannot be crystallized on the freezing pipe and other related equipment; the circulating water directly acts on the air cooling tower and does not pass through the water cooling tower, so that the consumption of the circulating water is reduced, the concentration multiple of the circulating water is further improved, the use amount of make-up water is saved, the problem that the circulating water is easy to crystallize under a low-temperature condition does not need to be considered, the use amount of a water quality stabilizer can be eliminated, and the agent cost for treating the circulating water is saved.

Description

Technical Field

[0001] This utility model relates to the field of air separation equipment technology, and in particular to a precooling system based on an air separation equipment. Background Technology

[0002] An air separation unit, also known as an air separation equipment or ASU (Air Separation Unit), is an industrial device used to separate the various components of air and produce gases such as oxygen, nitrogen, and argon. It typically includes a compression system, a precooling system, a purification system, a heat exchange system, a distillation system, a product delivery system, and a liquid storage backup system. The compressed air exiting the compression system reaches temperatures as high as approximately 100°C. Before entering the purification system, this high-temperature air must be pre-cooled by the precooling system.

[0003] In the prior art, the precooling system mainly includes: a circulating water tank, an air-cooled tower connected to the circulating water tank via a circulating pipe for precooling the compressed air, a water-cooled tower connected to the circulating water tank via a circulating pipe for cooling the circulating water, and a chiller unit connected at one end to the water-cooled tower and at the other end to the air-cooled tower for further cooling the circulating water. First, the circulating water in the circulating water tank, driven by the circulating water pump through the circulating pipe, partially enters the lower part of the air-cooled tower to serve as cooling water for the initial cooling of the compressed air entering the tower. The other part enters the water-cooled tower, where it undergoes initial cooling of the circulating water, forming chilled water. This chilled water then enters the chiller unit through the chilled water pipe under the action of the water pump for further cooling. The chilled water then enters the upper part of the air-cooled tower to further cool the compressed air, which has already undergone initial cooling. Finally, the cooled compressed air is transported through pipelines to the next system for further processing. The chilled water and cooling water, having undergone heat exchange, are discharged from the air-cooled tower by gravity. Driven by the residual pressure of the returning circulating water, they are transported through the circulating pipe to the cooling tower located at the top of the circulating water tank for further cooling before returning to the circulating water tank for the next cycle. This process is repeated continuously.

[0004] Because each circulation of the circulating water in the circulating water tank results in a loss, such as water vapor evaporating inside the cooling tower and carrying away heat, leaks in the circulating water pipes, and sewage discharge and backwashing of the circulating water system, it is necessary to continuously replenish the circulating water tank (with water from outside the pre-cooling system) to ensure a normal supply of circulating water. However, as the number of circulations of the circulating water increases, the ion concentration in the circulating water also increases, eventually forming high-ion-concentration circulating water. After being cooled by the water cooling tower, high-ion-concentration circulating water is very likely to crystallize on the inner walls of related equipment (such as chillers, water pumps and filters) and related pipes (such as refrigeration pipes), causing the related equipment to malfunction and the related pipes to become blocked. Utility Model Content

[0005] The purpose of this invention is to provide a precooling system based on an air separation unit to solve the problems mentioned in the background art.

[0006] The technical solution adopted in this utility model is:

[0007] A precooling system based on an air separation unit, comprising:

[0008] A circulating water tank that stores circulating water;

[0009] An air-cooled tower is connected to the circulating water tank via a circulation pipe, and the circulating water acts on the air inside the air-cooled tower through the circulation pipe;

[0010] The refrigeration equipment is connected to the air-cooled tower via refrigeration pipes;

[0011] The water replenishment system has one end connected to an external water source for the precooling system and the other end connected to the refrigeration equipment. The external water for the precooling system is transported to the refrigeration equipment through the water replenishment system. The refrigeration equipment cools the external water for the precooling system. The external water discharged from the refrigeration equipment is then transported to the air-cooled tower through the refrigeration pipe and acts on the air inside the air-cooled tower.

[0012] Optionally, the water replenishment system includes:

[0013] The water supply pipe has one end connected to an external water source for the precooling system and the other end connected to the refrigeration equipment.

[0014] Optionally, the water supply pipe is equipped with a third pressure gauge, a second platinum resistance thermometer, a second electromagnetic flowmeter, a regulating valve, and a fourth butterfly valve.

[0015] Optionally, the water replenishment system includes:

[0016] A water supply pipe, one end of which is connected to an external water source of the precooling system, and the other end of which is connected to the refrigeration equipment;

[0017] A pressurization component is installed on the water supply pipe.

[0018] Optionally, the water supply pipe is equipped with a first pressure gauge, a pressurization component, a second pressure gauge, a first platinum resistance thermometer, a first electromagnetic flowmeter, and a third butterfly valve.

[0019] Optionally, the booster assembly includes:

[0020] The first butterfly valve is installed on the water supply pipe;

[0021] A Y-type filter is installed on the water supply pipe, parallel to the first butterfly valve;

[0022] A pipeline booster pump is installed on the water supply pipe, parallel to the Y-type filter;

[0023] A one-way valve is installed on the water supply pipe, parallel to the pipeline booster pump;

[0024] The second butterfly valve is installed on the water supply pipe, in parallel with the one-way valve.

[0025] Optionally, the booster assembly adopts a one-for-one standby structure.

[0026] Optionally, the refrigeration device includes:

[0027] A water-cooled tower, one end of which is connected to an external water source for the precooling system via the water supply system, and the other end of which is connected to the air-cooled tower via the refrigeration pipe; and / or

[0028] The chiller unit has its input end connected to the water-cooled tower via the chilled pipe, and its output end connected to the air-cooled tower via the chilled pipe.

[0029] Optionally, a cooling water pump set is installed on the circulation pipe.

[0030] Optionally, a chilled water pump unit is installed on the chilled pipe.

[0031] Compared with the prior art, the beneficial effects of this utility model are:

[0032] In this invention, the replenished water is directly transported to the water-cooling tower through the water replenishment system, and the water-cooling tower cools the replenished water, instead of the prior art where the replenished water is first transported to the circulating water tank and then the circulating water is transported to the water-cooling tower through the circulating pipe. In this invention, the advantages of this treatment method are as follows: since the makeup water is unused and has a low ion concentration, even after cooling by a water-cooling tower and chiller unit, it will not crystallize on the refrigeration pipes and other related equipment (such as the chiller unit), thus avoiding adverse effects. Furthermore, in this invention, since the circulating water in the circulating water tank acts directly on the air-cooling tower without passing through the water-cooling tower, it not only reduces the consumption of circulating water but also further increases the concentration ratio of the circulating water, saving the amount of makeup water needed (the reduced consumption of circulating water and the further increase in the concentration ratio of the circulating water mean that the amount of makeup water needed to be added to the circulating water tank is also reduced). It also eliminates the need to consider the problem of crystallization of circulating water at low temperatures (as a heat exchanger, the temperature of the circulating water will only rise after heat exchange, not fall), thereby eliminating (or reducing) the amount of water quality stabilizer needed, saving on circulating water treatment reagent costs. Moreover, the temperature of the makeup water is lower than that of the circulating water, thus reducing the operating load of the chiller unit and saving on electricity costs. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of the first embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the water replenishment system structure in the first embodiment of this application;

[0036] Figure 3 This is a schematic diagram of the structure of the second embodiment of this application;

[0037] Figure 4 This is a schematic diagram of the water replenishment system structure in the second embodiment of this application.

[0038] Figure label:

[0039] 1. Circulating water tank; 11. Circulating pipe;

[0040] 2. Water-cooled tower; 21. Refrigeration pipe;

[0041] 3. Air-cooled tower; 31. Upper cooling zone; 311. Upper packing; 312. Upper water distributor; 32. Lower cooling zone; 321. Lower packing; 322. Lower water distributor;

[0042] 41. Water supply system; 411. First water supply pipe; 412. First pressure gauge; 413. Booster assembly; 4131. First butterfly valve; 4132. Y-type filter; 4133. Pipeline booster pump; 4134. Check valve; 4135. Second butterfly valve; 414. Second pressure gauge; 415. First platinum resistance thermometer; 416. First electromagnetic flowmeter; 417. Third butterfly valve; 418. Second water supply pipe;

[0043] 42. Water supply system; 421. Third water supply pipe; 422. Third pressure gauge; 423. Second platinum resistance thermometer; 424. Second electromagnetic flowmeter; 425. Regulating valve; 426. Fourth butterfly valve; 427. Fourth water supply pipe;

[0044] 5. Circulating water pump set; 6. Cooling water pump set; 7. Chiller unit; 8. Chilled water pump set; 9. Cooling tower. Detailed Implementation

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0047] The circulating water in the circulating water tank described below, also known as cooling water, is water that is repeatedly used and circulated within the precooling system; the makeup water is water that has not been used outside the precooling system and is generally taken from a reservoir or underground. The temperature of the circulating water is generally ≤30~32℃, and the temperature of the makeup water is lower than that of the circulating water because it is taken from a reservoir or underground.

[0048] First Embodiment

[0049] like Figure 1-2 As shown, this utility model embodiment provides a precooling system based on an air separation unit, including: a circulating water tank 1, an air-cooled tower 3, a water-cooled tower 2, and a water replenishment system 41, etc.

[0050] The circulating water tank 1 is configured as the main storage location for circulating water. The air-cooled tower 3 is connected to the circulating water tank 1 via a circulating pipe 11, and is configured as the main location for cooling compressed air. Circulating water from the circulating water tank 1 is transported to the air-cooled tower 3 via the circulating pipe 11, serving as cooling water for the initial heat exchange with the compressed air inside the air-cooled tower 3. One end of the makeup water system 41 is connected to an external water source (not shown in the figure) of the pre-cooling system, and the other end is connected to the water-cooled tower 2 and the circulating water tank 1. A portion of the makeup water is transported to the water-cooled tower 2 via the makeup water system 41, where it is cooled to form chilled water. The other portion is transported to the circulating water tank 1 via the makeup water system 41 to replenish the water supply to the circulating water tank 1. The water-cooled tower 2 is connected to the air-cooled tower 3 via a chilled pipe 21, and is configured as the main location for cooling the makeup water to form chilled water. The chilled water is transported to the air-cooled tower 3 via the chilled pipe 21, where it again exchanges heat with the compressed air inside the air-cooled tower 3.

[0051] Specifically, the air-cooled tower 3 is a vertical cylindrical tower structure, divided into upper and lower sections. The upper section is the upper cooling zone 31, and the lower section is the lower cooling zone 32. The upper cooling zone 31 contains upper packing material 311, and the lower cooling zone 32 contains lower packing material 321. An upper water distributor 312 is installed above the upper packing material 311, and a lower water distributor 322 is installed above the lower packing material 321. The upper water distributor 312 is connected to the chilled water pipe 21, and the lower water distributor 322 is connected to the circulation pipe 11. The circulating water in the circulation pipe 11, i.e., the cooling water, is evenly distributed onto the lower packing material 321 through the lower water distributor 322. The cooling water flows down through the gaps in the packing material and undergoes initial heat exchange with the compressed air flowing upwards. After the initial heat exchange, the compressed air continues to rise within the tower. The chilled water in the chilled pipe 21 is also evenly distributed onto the upper packing 311 through the upper water distributor 312. The chilled water flows down through the gaps in the packing and exchanges heat with the upward-flowing compressed air again. After two heat exchanges, the compressed air is discharged from the top of the air-cooled tower 3 for further processing, while the cooling water and chilled water after heat exchange are discharged from the bottom of the air-cooled tower 3 under gravity and finally flow into the circulating water pool 1 through the circulation pipe 11.

[0052] like Figure 2 As shown, the water replenishment system 41 includes: a first water replenishment pipe 411, a first pressure gauge 412, a pressurization component 413, a second pressure gauge 414, a first platinum resistance thermometer 415, a first electromagnetic flowmeter 416, a third butterfly valve 417, and a second water replenishment pipe 418, etc., arranged sequentially on the first water replenishment pipe 411.

[0053] One portion of the makeup water is transported to the water-cooling tower 2 via the first makeup water pipe 411, while the other portion is transported to the circulating water pool 1 via the second makeup water pipe 418.

[0054] A first pressure gauge 412 is configured to indicate the pressure before the pressurization assembly 413. The pressurization assembly 413 is configured to increase the pressure of the makeup water in the first makeup water pipe 411. A second pressure gauge 414 is configured to indicate the pressure after the pressurization assembly 413. A first platinum resistance thermometer 415 is configured to indicate and record the temperature of the makeup water to facilitate assessment of the system's cold energy recovery. A first electromagnetic flowmeter 416 is interlocked with a frequency converter (not shown) to ensure the stability of the makeup water flow rate into the water-cooled tower 2. A third butterfly valve 417 is configured to cut off the makeup water in the first makeup water pipe 411.

[0055] More specifically, the booster assembly 413 includes several parts arranged sequentially along the direction of the makeup water flow, such as a first butterfly valve 4131, a Y-type filter 4132, a pipeline booster pump 4133, a one-way valve 4134, and a second butterfly valve 4135.

[0056] The first electromagnetic flowmeter 416 is interlocked with the frequency converter, and the frequency of the pipeline booster pump 4133 is adjusted to ensure the stability of the replenishment water flow into the water-cooled tower 2.

[0057] The first butterfly valve 4131 is configured to cut off the makeup water supply, facilitating maintenance of the first pressure gauge 412. The Y-type filter 4132 is configured to filter out particulate matter mixed in the makeup water within the first makeup water pipe 411, preventing particulate matter from entering the pipeline booster pump 4133 and causing damage to it. The pipeline booster pump 4133 is configured to increase the pressure of the makeup water within the first makeup water pipe 411, ensuring smooth flow of the makeup water into the water-cooling tower 2. The check valve 4134 is configured to prevent backflow or backflow of makeup water within the first makeup water pipe 411, thereby protecting the pipeline booster pump 4133 and ensuring its normal operation. The second butterfly valve 4135 is also configured to cut off the makeup water supply, facilitating maintenance of the Y-type filter 4132, the pipeline booster pump 4133, and the check valve 4134.

[0058] Furthermore, to prevent accidents during the use of the pressurization component 413 that could cause the precooling system to malfunction, the pressurization component 413 in this embodiment adopts a one-for-one standby structure. That is, there are two sets of pressurization components 413, which are connected in parallel on the first water supply pipe 411. When one set of pressurization components 413 is in working condition, the other set is in standby condition. If one of the pressurization components 413 fails, the other pressurization component 413 will take over the operation of the previous pressurization component 413, thereby ensuring the normal operation of the precooling system.

[0059] In operation, the circulating water in the circulating water tank 1 is first transported to the air-cooled tower 3 via the circulating pipe 11. This serves as cooling water for the initial heat exchange with the compressed air in the lower cooling zone 32. After the initial heat exchange, the compressed air continues to rise within the tower. Simultaneously, a portion of the makeup water from outside the pre-cooling system is transported to the water-cooled tower 2 via the first makeup water pipe 411 under the action of the pipeline booster pump 4133. After being cooled in the water-cooled tower 2, it forms chilled water, which is then transported to the upper cooling zone 31 via the chilled water pipe 21 for another heat exchange with the rising compressed air. The compressed air, after two heat exchanges, is discharged from the top of the air-cooled tower 3 for further processing, while the cooled water and chilled water, after heat exchange, are discharged from the bottom of the air-cooled tower 3 under gravity and ultimately flow into the circulating water tank 1 for the next cycle. When it is necessary to replenish the circulating water in the circulating water tank 1, another portion of the makeup water is transported to the circulating water tank 1 via the second makeup water pipe 418.

[0060] Furthermore, to prevent the precooling system from malfunctioning due to unexpected situations with the external water supply, the circulation pipe 11 can also be connected to the first water supply pipe 411. When an unexpected situation occurs with the external water supply to the precooling system, the valve on the circulation pipe 11 is opened, and the circulating water in the circulation pipe 11 is transported to the first water supply pipe 411 through the circulation pipe 11. Then, the water is transported to the water-cooling tower 2 through the first water supply pipe 411. At this time, the circulating water will replace the supply water. The circulating water is cooled by the water-cooling tower 2 and then forms chilled water that acts on the air-cooling tower 3.

[0061] Furthermore, in order to improve the transmission efficiency of circulating water, a circulating water pump set 5 is installed on the circulating pipe 11 adjacent to the circulating water pool 1. As a preferred embodiment, the circulating water pump set 5 adopts a one-in-use and two-standby structure, that is, there are three sets of circulating water pump sets 5, which are connected in parallel on the circulating pipe 11.

[0062] Furthermore, in order to improve the efficiency of circulating water entering the air-cooled tower 3, a cooling water pump set 6 is installed on the circulation pipe 11 adjacent to the air-cooled tower 3. As a preferred embodiment, the cooling water pump set 6 adopts a one-for-one standby structure, that is, there are two sets of cooling water pump sets 6, which are connected in parallel on the circulation pipe 11.

[0063] Furthermore, to ensure the precooling system can operate normally even under extreme summer temperatures, the precooling system may also include a pair of chiller units 7 for further cooling of the chilled water. The input end of the chiller unit 7 is connected to the water-cooled tower 2 via a chilled pipe 21, and the output end is connected to the air-cooled tower 3 via a chilled pipe 21. As a preferred embodiment, the chiller unit 7 also adopts a one-for-one standby structure, that is, there are two chiller units 7, which are connected in parallel on the chilled pipe 21.

[0064] Furthermore, in order to improve the transmission efficiency of chilled water, a chilled water pump set 8 is installed on the chilled pipe 21. As a preferred embodiment, the chilled water pump set 8 adopts a one-for-one standby structure, that is, there are two sets of chilled water pump sets 8, which are connected in parallel on the chilled pipe 21.

[0065] Furthermore, in order to further cool the chilled water and cooling water after heat exchange, a cooling tower 9 is installed in the circulating water tank 1. The chilled water and cooling water discharged from the air-cooled tower 3 are first discharged into the cooling tower 9 through the circulation pipe 11 for cooling treatment, and then flow back into the circulating water tank 1. In a preferred embodiment, there are multiple cooling towers 9.

[0066] In the second embodiment, as Figure 3-4 As shown, one end of the water replenishment system 42 is connected to an external water source (not shown in the figure) of the precooling system, and the other end is connected to the water cooling tower 2 and the circulating water pool 1.

[0067] Specifically, such as Figure 4 As shown, the water replenishment system 42 includes: a third water replenishment pipe 421, a third pressure gauge 422, a second platinum resistance thermometer 423, a second electromagnetic flowmeter 424, a regulating valve 425, a fourth butterfly valve 426, and a fourth water replenishment pipe 427, which are sequentially installed on the third water replenishment pipe 421 along the direction of water flow.

[0068] The system includes a third pressure gauge 422 configured to indicate the pressure inside the third water supply pipe 421. A second platinum resistance thermometer 423 configured to indicate and record the temperature of the makeup water to facilitate assessment of the system's cold energy recovery. A second electromagnetic flowmeter 424 configured to display the flow rate of the makeup water in the third water supply pipe 421. A regulating valve 425 configured to adjust the flow rate of the makeup water in the third water supply pipe 421 based on the monitoring value of the second electromagnetic flowmeter 424. A fourth butterfly valve 426 configured to shut off the makeup water in the third water supply pipe 421.

[0069] All other contents are the same as those described in the first embodiment, and will not be repeated here.

[0070] It should be noted that the water-cooled tower 2, air-cooled tower 3, chiller unit 7, cooling tower 9, circulating water pump unit 5, cooling water pump unit 6, chilled water pump unit 8, first electromagnetic flowmeter 416 and frequency converter interlocking to achieve adjustment of the frequency of pipeline booster pump 4133 are all existing technologies and will not be elaborated here.

[0071] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A precooling system based on an air separation unit, characterized in that, include: A circulating water tank stores circulating water; an air-cooled tower is connected to the circulating water tank via a circulating pipe, and the circulating water acts on the air inside the air-cooled tower through the circulating pipe. The refrigeration equipment is connected to the air-cooled tower via refrigeration pipes. The water supply system has one end connected to an external water source for the precooling system and the other end connected to the refrigeration equipment. The external water for the precooling system is transported to the refrigeration equipment via the water supply system, where it is cooled. The water discharged from the refrigeration equipment is then transported to the air-cooled tower via the refrigeration pipes, where it acts on the air inside the air-cooled tower.

2. The precooling system according to claim 1, characterized in that, The water replenishment system includes a water replenishment pipe, one end of which is connected to an external water source of the precooling system, and the other end of which is connected to the refrigeration equipment.

3. The precooling system according to claim 2, characterized in that, The water supply pipe is equipped with a third pressure gauge, a second platinum resistance thermometer, a second electromagnetic flowmeter, a regulating valve, and a fourth butterfly valve.

4. The precooling system according to claim 1, characterized in that, The water replenishment system includes: a water replenishment pipe, one end of which is connected to an external water source of the precooling system, and the other end of which is connected to the refrigeration equipment; and a pressurization component, which is installed on the water replenishment pipe.

5. The precooling system according to claim 4, characterized in that, The water supply pipe is equipped with a first pressure gauge, a pressurization component, a second pressure gauge, a first platinum resistance thermometer, a first electromagnetic flowmeter, and a third butterfly valve.

6. The precooling system according to claim 4, characterized in that, The pressurization assembly includes: a first butterfly valve, disposed on the water supply pipe; a Y-type filter, disposed on the water supply pipe, parallel to the first butterfly valve; a pipeline booster pump, disposed on the water supply pipe, parallel to the Y-type filter; a one-way valve, disposed on the water supply pipe, parallel to the pipeline booster pump; and a second butterfly valve, disposed on the water supply pipe, parallel to the one-way valve.

7. The precooling system according to claim 4 or 6, characterized in that, The booster assembly adopts a one-for-one standby structure.

8. The precooling system according to claim 1, characterized in that, The refrigeration equipment includes: a water-cooled tower, one end of which is connected to an external water source of the precooling system through the water replenishment system, and the other end of which is connected to the air-cooled tower through the refrigeration pipe; and / or a chiller unit, the input end of which is connected to the water-cooled tower through the refrigeration pipe, and the output end of which is connected to the air-cooled tower through the refrigeration pipe.

9. The precooling system according to claim 1, characterized in that, A cooling water pump unit is installed on the circulation pipe.

10. The precooling system according to claim 1, characterized in that, A chilled water pump unit is installed on the chilled pipe.

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