Precooling system and air separation unit

Abstract

The present application relates to the technical field of air separation equipment, and in particular to a precooling system and an air separation device, wherein the precooling system comprises a water chiller, a water cooling tower, an air cooling tower and a cold storage unit, wherein the cold storage unit is configured to be able to input, output and store cold energy, and the cold storage unit is connected to the water chiller, the water cooling tower and the air cooling tower respectively, so that the cold energy can be moved between the cold storage unit and the water chiller, between the cold storage unit and the water cooling tower, and between the cold storage unit and the air cooling tower. According to the precooling system and the air separation device provided by the present application, by storing and releasing cold energy in the cold storage unit, both the water chiller and the water cooling tower can be kept running under high-efficiency load regardless of whether they are in a high-temperature environment or a low-temperature environment, thereby effectively improving the working efficiency of the precooling system, improving the utilization rate of the cold energy in the low-temperature environment of the precooling system, and saving energy.

Description

Technical Field

[0001] The present application relates to the technical field of air separation equipment, and in particular to a precooling system and an air separation unit. Background Art

[0002] Air separation, referred to as air separation, refers to the process of separating its components (oxygen, nitrogen, argon, helium and other rare gases) from air by applying the principle of low-temperature refrigeration. Generally, the air is compressed and cooled to a very low temperature, or liquefied by expansion, and then separated in a distillation tower.

[0003] In order to improve the efficiency of the air separation unit, a pre-cooling system is usually set up in the air separation unit to reduce the temperature of the process gas so that the process gas can be compressed to a higher pressure when it is subsequently compressed and have a good throttling and cooling effect.

[0004] However, today's precooling systems usually include chillers, water cooling towers and air cooling towers. Today's precooling systems have unbalanced cooling requirements when working in different temperature environments. For example, when the precooling system operates in a high temperature environment (such as during the summer day), the chillers and water cooling towers are in high-load operation to meet the cooling requirements of the air cooling tower in the high temperature environment; for another example, when the precooling system operates in a low temperature environment (such as at night in winter), the chillers and water cooling towers are in low-load operation to provide cooling for the air cooling tower, and a large amount of cooling capacity is not fully utilized. When the chiller is operating at a large load or a small load, the chiller's working efficiency is low. This makes the working efficiency of the precooling system greatly affected by the ambient temperature. Summary of the invention

[0005] The purpose of the present application is to provide a precooling system and an air separation device, so as to solve, to a certain extent, the technical problem in the prior art that the precooling system has an unbalanced cooling demand when working in different temperature environments, so that the working efficiency of the precooling system is greatly affected by the ambient temperature.

[0006] According to a first aspect of the present application, a precooling system is provided, comprising a water chiller, a water cooling tower, an air cooling tower and a cold storage unit, wherein the cold storage unit is configured to be capable of inputting, outputting and storing cold energy, and the cold storage unit is respectively connected to the water chiller, the water cooling tower and the air cooling tower, so that the cold energy can be moved between the cold storage unit and the water chiller, between the cold storage unit and the water cooling tower, and between the cold storage unit and the air cooling tower.

[0007] Preferably, the energy storage circulation pipeline includes:

[0008] A first energy storage branch is connected to the chiller and the cold storage part respectively;

[0009] A first driving unit, disposed in the first energy storage branch, to drive cold energy from the cold storage unit to flow to the chiller via the first energy storage branch;

[0010] The second energy storage branch is connected to the chiller and the cold storage part respectively, so as to transfer cold energy from the chiller to the cold storage part.

[0011] Preferably, it also includes:

[0012] A first liquid storage chamber is arranged in the water cooling tower;

[0013] A first cooling branch is connected to the first liquid storage chamber and the cooling storage part respectively;

[0014] The second cooling branch is connected to the first liquid storage chamber and the first energy storage branch respectively.

[0015] Preferably, it also includes:

[0016] A third cooling branch is connected to the first liquid storage chamber and the air cooling tower respectively;

[0017] A second driving unit is provided in the third cooling branch to drive the cooling capacity in the third cooling branch to flow to the air cooling tower;

[0018] The fourth cooling branch connects the second energy storage branch with a portion of the third cooling branch located on the upstream side of the second driving unit.

[0019] Preferably, it also includes:

[0020] A first control valve is provided in the first energy storage branch to control the amount of cold flowing from the cold storage part to the chiller;

[0021] A second control valve is provided in the second cooling branch to control the cooling amount flowing from the first liquid storage chamber to the chiller;

[0022] a third control valve, arranged in the fourth cooling branch, to control the cooling capacity of the chiller flowing to the air cooling tower;

[0023] a fourth control valve, arranged in the second energy storage branch, to control the amount of cold water flowing from the chiller to the cold storage part;

[0024] A fifth control valve is provided in the third cooling branch to control the cooling amount flowing from the first liquid storage chamber to the air cooling tower.

[0025] Preferably, it also includes a circulating water inflow pipeline and a dirty nitrogen pipeline, and the circulating water inflow pipeline and the dirty nitrogen pipeline are both connected to the water cooling tower;

[0026] When the water cooling tower is in use, the circulating water inflow pipeline is located above the dirty nitrogen pipeline in the direction of gravity, and the first liquid storage chamber is located below the dirty nitrogen pipeline in the direction of gravity.

[0027] Preferably, the contaminated nitrogen pipeline comprises:

[0028] A flow monitoring unit for detecting the gas flow in the contaminated nitrogen pipeline;

[0029] The first temperature detection unit is used to detect the temperature of the gas in the dirty nitrogen pipeline.

[0030] Preferably, it further comprises a process gas inlet pipeline, a process gas outflow pipeline and a circulating water outflow pipeline, wherein the process gas inlet pipeline, the process gas outflow pipeline and the circulating water outflow pipeline are all connected to the air cooling tower;

[0031] The air cooling tower further comprises a second liquid storage chamber, wherein the second liquid storage chamber is arranged at the bottom of the air cooling tower;

[0032] The circulating water outflow pipeline is in communication with the second liquid storage chamber;

[0033] When the water cooling tower is in use, the process gas outflow pipeline is located above the third cooling branch in the direction of gravity, and the process gas inflow pipeline is located below the third cooling branch in the direction of gravity.

[0034] Preferably, the cold storage unit further comprises a storage window, through which cold energy can be stored in and taken out of the cold storage unit;

[0035] The cold storage part is a liquid storage container with heat preservation function;

[0036] The precooling system further includes a liquid level detection unit and a second temperature detection unit, and both the liquid level detection unit and the second temperature detection unit are disposed in the liquid storage container.

[0037] According to the second aspect of the present application, an air separation device is provided, comprising the precooling system described in any of the above technical solutions, and thus having all the beneficial technical effects of the precooling system, which will not be described in detail herein.

[0038] Compared with the prior art, the beneficial effects of this application are:

[0039] The precooling system provided by the present application is to connect the cold storage part with the chiller, the water cooling tower and the air cooling tower respectively, so that the cold energy can be moved between the cold storage part and the chiller, between the cold storage part and the water cooling tower, and between the cold storage part and the air cooling tower. When the precooling system is in a low temperature environment and the cold energy demand is low, the precooling system can transfer the excess cold energy generated by the chiller and / or the water cooling tower to the cold storage part via the energy storage circulation pipeline for storage; when the precooling system is in a high temperature environment and the cold energy demand is high, the precooling system can provide the cold energy stored in the cold storage part to the chiller and / or the air cooling tower to supplement the insufficient cold energy produced by both the chiller and the water cooling tower. In other words, the precooling system provided by the present application, through the storage and release of cold energy in the cold storage part, enables both the chiller and the water cooling tower to operate under high efficiency load regardless of whether they are in a high temperature environment or a low temperature environment, effectively improving the working efficiency of the precooling system.

[0040] In addition, the excess cold energy generated in the low-temperature environment is stored in the cold storage unit, which effectively improves the utilization rate of the cold energy in the low-temperature environment of the pre-cooling system and saves energy.

[0041] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 A schematic diagram of the process structure of the precooling system provided in an embodiment of the present application.

[0044] Reference numerals:

[0045] 1-cold storage unit; 12-first energy storage branch; 2-water chiller; 21-second energy storage branch; 3-water cooling tower; 311-first cooling branch; 312-second cooling branch; 313-third cooling branch; 314-fourth cooling branch; 32-dirty nitrogen pipeline; 33-circulating water inflow pipeline; 4-air cooling tower; 41-process gas inflow pipeline; 42-circulating water outflow pipeline; 43-process gas outflow pipeline; 5-first drive unit; 6-second drive unit; 71-first control valve; 72-second control valve; 73-third control valve; 74-fourth control valve; 75-fifth control valve; 76-sixth control valve; 77-seventh control valve;

[0046] L1-first liquid level detection unit; L2-second liquid level detection unit; L3-third liquid level detection unit;

[0047] T1-first temperature detection unit; T2-second temperature detection unit; T3-third temperature detection unit; T4-fourth temperature detection unit; T5-fifth temperature detection unit; T6-sixth temperature detection unit; T7-seventh temperature detection unit;

[0048] F1-first flow detection unit; F2-second flow detection unit; F3-third flow detection unit; F4-fourth flow detection unit;

[0049] P1-first pressure detection unit; P2-second pressure detection unit; P3-third pressure detection unit. DETAILED DESCRIPTION

[0050] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0051] The components of the embodiments of the present application generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed, but merely represents the selected embodiments of the present application.

[0052] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0053] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0054] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] Refer to the following Figure 1 The present invention describes a precooling system and an air separation unit according to some embodiments of the present application.

[0056] See also Figure 1 As shown, an embodiment of the first aspect of the present application provides a precooling system, which includes a chiller 2, a water-cooling tower 3, an air-cooling tower 4 and a cold storage part 1, wherein the cold storage part 1 is configured to be able to input, output and store cold energy, and the cold storage part 1 is respectively connected to the chiller 2, the water-cooling tower 3 and the air-cooling tower 4 so that the cold energy can be moved between the cold storage part 1 and the chiller 2, between the cold storage part 1 and the water-cooling tower 3, and between the cold storage part 1 and the air-cooling tower 4. In this way, by connecting the cold storage part 1 to the chiller 2, the water-cooling tower 3 and the air-cooling tower 4, respectively, the cold energy can be moved between the cold storage part 1 and the chiller 2, between the cold storage part 1 and the water-cooling tower 3, and between the cold storage part 1 and the air-cooling tower 4. When the precooling system is in a low-temperature environment and the demand for cold capacity is low, the precooling system can transfer the excess cold capacity generated by the chiller 2 and / or the water-cooling tower 3 to the cold storage part 1 for storage via the energy storage circulation pipeline; when the precooling system is in a high-temperature environment and the demand for cold capacity is high, the precooling system can provide the cold capacity stored in the cold storage part 1 to the chiller 2 and / or the air-cooling tower 4 to supplement the insufficient cold capacity of both the chiller 2 and the water-cooling tower 3. In other words, the precooling system provided in the present application, through the storage and release of cold capacity by the cold storage part 1, enables both the chiller 2 and the water-cooling tower 3 to operate under high-efficiency load regardless of whether they are in a high-temperature environment or a low-temperature environment, thereby effectively improving the working efficiency of the precooling system. In addition, the excess cold capacity generated in the low-temperature environment is stored in the cold storage part 1, which effectively improves the utilization rate of the cold capacity of the low-temperature environment of the precooling system and saves energy.

[0057] Preferably, if Figure 1As shown, the energy storage circulation pipeline may include a first energy storage branch 12, a second energy storage branch 21 and a first driving unit 5, wherein the first driving unit 5 is arranged on the first energy storage branch 12, and both the first energy storage branch 12 and the second energy storage branch 21 are connected to both the chiller 2 and the cold storage part 1, so that the cold energy can flow from the cold storage part 1 to the chiller 2 via the first energy storage branch 12, and the cold energy can flow from the chiller 2 to the cold storage part 1 via the second energy storage branch 21.

[0058] Preferably, if Figure 1 As shown, the precooling system may further include a first control valve 71 , which is disposed in the first energy storage branch 12 to control the amount of cold flowing from the cold storage unit 1 into the first energy storage branch 12 .

[0059] Preferably, if Figure 1 As shown, the precooling system may further include a first pressure detection unit P1, which may be disposed at a position of the first energy storage branch 12 located downstream of the first driving unit 5 to detect pressure information of the cooling fluid in the pipeline at the outlet of the first driving unit 5 of the first energy storage branch 12.

[0060] Preferably, if Figure 1 As shown, the precooling system may further include a second flow detection unit F2, which may be disposed at a position of the first energy storage branch 12 located downstream of the first driving unit 5 to detect the flow information of the cooling fluid at the outlet of the first driving unit 5 of the first energy storage branch 12. In this way, the amount of cooling that flows from the cold storage unit 1 to the water cooling group can be obtained through the information collected by the first pressure detection unit P1 and the first flow detection unit F1.

[0061] Preferably, if Figure 1 As shown, the precooling system may further include a fourth control valve 74 , which is disposed in the second energy storage branch 21 to control the amount of cold flowing from the chiller 2 to the cold storage part 1 via the second energy storage branch 21 .

[0062] Optionally, the precooling system may further include a second pressure detection unit P2 and a third temperature detection unit T3, both of which are arranged at a position of the second energy storage branch 21 close to the interface of the chiller 2 to detect the pressure and temperature of the cooling fluid flowing out of the chiller 2 respectively, so as to obtain the cooling capacity flowing from the cold storage part 1 to the water cooling group.

[0063] In an embodiment, Figure 1 As shown, the precooling system may further include a first liquid storage chamber, which is disposed in the water cooling tower 3 and is used to store circulating water cooled by the water cooling tower 3 .

[0064] like Figure 1As shown, the precooling system may further include a circulating water inlet pipeline 33 and a dirty nitrogen gas pipeline 32, wherein the circulating water inlet pipeline 33 and the dirty nitrogen gas pipeline 32 are both connected to the water cooling tower 3, so that the circulating water entering the water cooling tower 3 exchanges heat and mass with the dry dirty nitrogen gas, and the dry dirty nitrogen gas absorbs the moisture of the circulating water, so that the circulating water is forced to evaporate and the cooling generated by the cooling can be temporarily stored in the above-mentioned first liquid storage chamber.

[0065] Alternatively, if Figure 1 As shown, the precooling system may further include a sixth control valve 76 , which is disposed in the circulating water inflow pipeline 33 to control the amount of circulating water flowing into the water cooling tower 3 from the circulating water inflow pipeline 33 .

[0066] Alternatively, if Figure 1 As shown, the above-mentioned dirty nitrogen gas pipeline 32 may also include a first flow monitoring unit and a first temperature detection unit T1 to detect the gas flow rate and the gas temperature in the dirty nitrogen gas pipeline 32. In this way, the control of the cooling capacity of the dirty nitrogen gas can be improved by monitoring the flow rate and temperature of the dirty nitrogen gas.

[0067] Preferably, if Figure 1 As shown, when the water-cooling tower 3 is in use, the circulating water inflow pipeline 33 is located above the dirty nitrogen pipeline 32 in the gravity direction, and the first liquid storage chamber is located below the dirty nitrogen pipeline 32 in the gravity direction. In this way, the circulating water entering the water-cooling tower 3 can meet the dirty nitrogen by relying on the effect of gravity, and after the circulating water completes the heat and mass exchange with the dirty nitrogen, it can still fall into the first liquid storage chamber by relying on the effect of gravity, which effectively reduces the energy consumption of the heat exchange between the water-cooling tower 3 and the dirty nitrogen.

[0068] Optionally, the water cooling tower 3 may further include an exhaust port, which is located at the top of the water cooling tower 3, so that the gas generated after the circulating water and the polluted nitrogen complete the heat exchange can be discharged from the water cooling tower 3 through the exhaust port.

[0069] Preferably, if Figure 1 As shown, the precooling system may further include a first cooling branch 311, which is connected to the first liquid storage chamber and the cold storage part 1 respectively to achieve connectivity between the water cooling tower 3 and the cold storage part 1. When the water cooling tower 3 has excess cooling capacity, the cold capacity may be transferred to the cold storage part 1 for storage through the first cooling branch 311.

[0070] Preferably, if Figure 1As shown, the first liquid storage chamber may further include a second liquid level detection unit L2 for detecting the water level of the cooling circulating water in the first liquid storage chamber, so as to confirm whether the system is operating normally through the water level of the first liquid storage chamber. If it is not operating normally, such as when the pipeline is blocked, the water level of the first liquid storage chamber will show a rapid rise in the liquid level, and if the pipeline is broken, the water level of the first liquid storage chamber will show a rapid drop in the liquid level.

[0071] Preferably, if Figure 1 As shown, the precooling system can also have a second cooling branch 312, which is connected to the first liquid storage chamber and the first energy storage branch 12 respectively, so that the cooling capacity of the water cooling tower 3 can be transferred to the chiller 2 through the second cooling branch 312 and the first energy storage branch 12 in sequence, so that the cooling water obtains part of the cooling capacity in the water cooling tower 3 and obtains another part of the cooling capacity in the chiller 2 to meet the system operation.

[0072] Alternatively, if Figure 1 As shown, the second cooling branch 312 may further include a second control valve 72 to control the second cooling branch 312 to transfer cold energy to the first energy storage branch 12 .

[0073] Preferably, if Figure 1 As shown, the second cooling branch 312 is connected to the portion of the first energy storage branch 12 located on the upstream side of the first driving unit 5, so that the first driving unit 5 can provide power for the cold energy to flow from the second cooling branch 312 to the first energy storage branch 12.

[0074] Preferably, if Figure 1 As shown, the precooling system may further include a third cooling branch 313 , which may be connected to the first liquid storage chamber and the air cooling tower 4 respectively, so that the water cooling tower 3 directly supplies cooling to the air cooling tower 4 .

[0075] Alternatively, if Figure 1 As shown, the third cooling branch 313 may further include a fifth control valve 75 to control the third cooling branch 313 to transfer cooling energy to the air cooling tower 4 .

[0076] Preferably, if Figure 1 As shown, the precooling system may further include a second driving unit 6 , which is disposed in the third cooling branch 313 to drive the cooling capacity in the third cooling branch 313 to flow toward the air cooling tower 4 .

[0077] Preferably, if Figure 1 As shown, the precooling system may further include a third pressure detection unit P3, which is arranged at a portion of the third cooling branch 313 located on the downstream side of the second driving unit 6 to detect the pipeline pressure of a portion of the third cooling branch 313 located on the downstream side of the second driving unit 6.

[0078] Preferably, if Figure 1 As shown, the precooling system may further include a fourth temperature detection unit T4, which is disposed at a portion of the third cooling branch 313 located on the downstream side of the second driving unit 6 to detect the temperature of the circulating water flowing into the air cooling tower 4.

[0079] Preferably, if Figure 1 As shown, the precooling system may further include a third flow detection unit F3, which is arranged at a portion of the third cooling supply branch 313 located on the downstream side of the second driving unit 6 to detect the flow of circulating water flowing into the air cooling tower 4. In this way, the cooling capacity carried by the circulating water flowing into the air cooling tower 4 can be determined based on the information detected by the third pressure detection unit P3, the fourth temperature detection unit T4 and the third flow detection unit F3.

[0080] In an embodiment, Figure 1 As shown, the precooling system may further include a fourth cooling branch 314 , which connects the second energy storage branch 21 with a portion of the third cooling branch 313 located on the upstream side of the second driving unit 6 , so as to enable the chiller 2 to supply cooling to the air cooling tower 4 .

[0081] Alternatively, if Figure 1 As shown, the fourth cooling branch 314 may include a third control valve 73 to control the amount of cooling that flows from the cooling unit to the air cooling tower 4.

[0082] In an embodiment, Figure 1 As shown, the air cooling tower 4 may further include a second liquid storage chamber, which is disposed at the bottom of the air cooling tower 4 to recover circulating water that completes heat and mass exchange with the process gas.

[0083] Preferably, if Figure 1 As shown, the precooling system may further include a process gas inlet pipeline 41, a process gas outlet pipeline 43, and a circulating water outlet pipeline 42. The process gas inlet pipeline 41, the process gas outlet pipeline 43, and the circulating water outlet pipeline 42 are all connected to the air cooling tower 4 to realize heat and mass exchange between the process gas and the circulating water in the air cooling tower 4.

[0084] Preferably, if Figure 1 As shown, the circulating water outflow pipeline 42 is connected to the second liquid storage chamber to facilitate the discharge of the circulating water in the second liquid storage chamber.

[0085] Alternatively, if Figure 1 As shown, the circulating water outflow pipeline 42 may further include a seventh control valve 77 to control the circulating water in the second liquid storage chamber to be discharged through the circulating water outflow pipeline 42 .

[0086] Alternatively, if Figure 1As shown, the circulating water outflow pipeline 42 may further include a seventh temperature detection unit T7, which is used to detect the temperature of the circulating water discharged from the second liquid storage chamber.

[0087] Preferably, if Figure 1 As shown, the second liquid storage chamber may further include a third liquid level detection portion L3 for detecting the water level of the cooling circulating water in the second liquid storage chamber.

[0088] Preferably, if Figure 1 As shown, when the water cooling tower 3 is in use, the process gas outflow pipeline 43 is located above the third cooling branch 313 in the direction of gravity, and the process gas inlet and outlet pipeline is located below the third cooling branch 313 in the direction of gravity. In this way, the circulating water carrying the cold capacity transported by the third cooling branch 313 enters the water cooling tower 3 and can meet the process gas by the action of gravity. After completing the heat exchange with the process gas, the circulating water can still fall into the second liquid storage chamber by the action of gravity, which effectively reduces the energy consumption of the heat exchange between the circulating water and the process gas.

[0089] Preferably, if Figure 1 As shown, the process gas inflow pipeline 41 also includes a sixth temperature control unit for detecting the temperature of the process gas flowing into the air cooling tower 4 .

[0090] Preferably, if Figure 1 As shown, the process gas outflow pipeline 43 is connected to the top of the air cooling tower 4 so that the process gas after heat exchange can be discharged from the air tower.

[0091] Alternatively, if Figure 1 As shown, the process gas outflow pipeline 43 may further include a fourth flow detection unit F4 and a fifth temperature detection unit T5 for detecting the temperature and flow of the process gas discharged from the air cooling tower 4 to obtain cooling capacity information of the process gas discharged from the air cooling tower 4 .

[0092] Preferably, the cold storage part 1 can be a liquid storage container with a heat preservation function, for example, a water tank with a heat preservation structure.

[0093] It should be noted that the above-mentioned cold energy can be transferred in the above-mentioned pipelines and stored in the cold storage part 1 using the above-mentioned circulating water as a carrier, but is not limited to circulating water. As long as it can carry the cold energy and transfer it in the various pipelines of the precooling system, the cold energy can also be carried by other medium fluids.

[0094] Preferably, not shown, the cold storage part 1 may further include a storage window, through which cold energy can be stored in and taken out of the cold storage part 1. On the one hand, once the above-mentioned chiller 2 and / or air cooling tower 4 is damaged, cold energy (for example, ice cubes or ice water) can be stored in the cold storage part 1 through the storage window to ensure the normal operation of the pre-cooling system and avoid maintenance shutdown; on the other hand, if the cold storage part 1 stores excess cold energy, the excess cold energy can be taken out from the cold storage part 1 through the storage window, thereby ensuring the cold storage energy of the cold storage part 1.

[0095] Optionally, both the first driving unit 5 and the second driving unit 6 may be water pumps.

[0096] Preferably, if Figure 1 As shown, the precooling system further includes a first liquid level detection part L1 and a second temperature detection part T2. The first liquid level detection part L1 and the second temperature detection part T2 are both arranged in the liquid storage container so as to obtain the cold amount stored in the liquid storage container.

[0097] Optionally, the first control valve 71, the second control valve 72, the third control valve 73, the fourth control valve 74, the fifth control valve 75, the sixth control valve 76 and the seventh control valve 77 may be electromagnetic flow valves. The above-mentioned control of the cooling capacity of the corresponding pipeline by each control valve can be understood as controlling the flow rate of the circulating water carrying the cooling capacity in the pipeline by the battery flow valve to achieve the control of the cooling capacity.

[0098] Optionally, the first liquid level detection part L1 , the second liquid level detection part L2 and the third liquid level detection part L3 may all be liquid level sensors.

[0099] Optionally, the first temperature detection unit T1 , the second temperature detection unit T2 , the third temperature detection unit T3 , the fourth temperature detection unit T4 , the fifth temperature detection unit T5 , the sixth temperature detection unit T6 , and the seventh temperature detection unit T7 may all be thermometers.

[0100] Optionally, the first flow detection part F1, the second flow detection part F2, the third flow detection part F3 and the fourth flow detection part F4 may be flow meters.

[0101] Optionally, the first pressure detection part P1, the second pressure detection part P2 and the third pressure detection part P3 may be pressure sensors or pressure gauges.

[0102] Preferably, the chiller 2 may be a device that generates cooling energy using a reverse Carnot cycle.

[0103] Based on the characteristics described above, Figure 1The chiller 2 is described as a precooling system of a device that uses a reverse Carnot cycle to produce cold energy. The following specifically describes the applicable states of the precooling system provided by the present application under different working conditions.

[0104] It should be noted that, for equipment that utilizes the reverse Carnot cycle to generate refrigeration, the most efficient equipment load operating range is usually 45% to 75%.

[0105] System operating condition 1: Under the premise that the equipment load of the chiller 2 meets the operating condition of 45-75%, when the chiller 2 can meet the cooling demand of the air cooling tower 4, at this time, the third control valve 73 is opened and the second control valve 72 is closed, so that the chiller 2 supplies cooling to the air cooling tower 4.

[0106] If there is still surplus cooling capacity in the chiller 2 at this time, the fourth control valve 74 is opened so that the surplus cooling capacity is transferred to the cold storage part 1 for storage via the second energy storage branch 21 .

[0107] System operating condition 2: The cooling capacity in the cold storage unit 1 is sufficient, and the system requires the chiller 2 to operate at a condition lower than 45% of the equipment load (i.e., the cooling capacity of the air cooling tower 4 is small, such as a low temperature environment);

[0108] At this time, the chiller 2 can still be kept running under the optimal working condition (equipment load meets the working condition of 45-75%), and the fourth control valve 74 is opened to transfer the remaining cold energy to the cold storage part 1 for storage via the second energy storage branch 21.

[0109] Alternatively, at this time, the chiller 2 is turned off, and the first control valve 71 and the third control valve 73 are opened, so that the cold storage part 1 directly supplies cold to the air cooling tower 4.

[0110] System operating condition three: the cooling capacity in the cold storage unit 1 is insufficient, and the system requires the chiller 2 to operate at a condition lower than 45% of the equipment load (i.e., the cooling capacity of the air cooling tower 4 is small, such as a low temperature environment);

[0111] At this time, the chiller 2 is kept running under the optimal working condition, and the third control valve 73 and the fourth control valve 74 are opened, so that the chiller 2 supplies cooling to the air cooling tower 4 while the remaining cooling capacity is transferred to the cold storage part 1 for storage via the second energy storage branch 21 .

[0112] System operating condition 4: The cooling capacity in the cold box is sufficient, and the system requires the chiller 2 to operate at a condition higher than 75% of the equipment load (i.e., the cooling capacity of the air cooling tower 4 is large, such as a high temperature environment);

[0113] At this time, the equipment load of the chiller 2 is maintained at 75%, the first control valve 71 and the third control valve 73 are opened, and the cold energy stored in the cold storage unit 1 is used to compensate for the insufficient refrigeration of the chiller 2 .

[0114] System operating condition five: When the cooling capacity in the cold box is insufficient, when the entire system requires chiller 2 to operate at a condition higher than 75% of the equipment load, all the cooling capacity comes from chiller 2. Chiller 2 is forced to operate at the required load. At this time, the refrigeration efficiency is slightly lower. This situation needs to be avoided.

[0115] At this time, the load of the chiller 2 can be reduced by releasing cold energy from the storage window to the cold storage part 1 or by opening the second control valve 72 and / or the fifth control valve 75 .

[0116] Abnormal working conditions: In the case of damage to the chiller 2 or the air-cooling tower 4, the cold capacity can be released to the cold storage part 1 through the storage window to ensure the normal operation of the pre-cooling system and the stability of the pre-cooling system.

[0117] In addition, in addition to adjusting the use status of the precooling system according to the above working conditions, the precooling system provided by the present application can also combine the local climate and meteorological changes to estimate the cooling capacity required each month or even each week, and estimate the cooling capacity required to be stored in the water tank each month or even each week based on data calculation and empirical values, and combine all the flow meters, thermometers, pressure gauges, liquid level gauges and valve data of the system to make an estimate of the working conditions of the precooling system of a certain project at a certain location, and make reference to the previous data in the subsequent operation to make advance intervention in the control system to compensate for the lag of the negative feedback regulation of the system. The stability of the overall system can be optimized by optimizing the control system on the basis of the original process optimization, and the operating efficiency of the precooling system can be greatly improved after the double optimization.

[0118] According to the precooling system provided in the present application, the paths through which the circulating water can flow to obtain cold in the water cooling tower 3 are effectively increased, specifically including:

[0119] Path one: the circulating water obtained by the water cooling tower 3 can flow to the cold storage part 1 through the first cold supply branch 311 for storage.

[0120] Path two, the circulating water obtained by the water cooling tower 3 can enter the first energy storage branch 12 through the second cooling branch 312 and flow to the chiller 2.

[0121] Path three, the circulating water obtained by the water-cooling tower 3 can directly provide cooling to the air-cooling tower 4 via the third cooling branch 313 .

[0122] In this way, the flexibility of cold transfer in the precooling system is effectively improved.

[0123] In addition, when the cooling capacity required by the process gas is small, the precooling system can provide a large surplus of cooling capacity. At this time, the chiller 2 is operated under the most efficient working condition, using the least energy to obtain the most cooling capacity, which is stored in the cold storage part 1, effectively improving the energy utilization and working efficiency of the precooling system.

[0124] The embodiment of the second aspect of the present application also provides an air separation device, including the precooling system described in any of the above embodiments, and thus has all the beneficial technical effects of the precooling system, which will not be repeated here.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A precooling system, characterized in that: The invention comprises a water chiller, a water cooling tower, an air cooling tower and a cold storage part, wherein the cold storage part is configured to be able to input, output and store cold energy, and the cold storage part is respectively connected with the water chiller, the water cooling tower and the air cooling tower, so that the cold energy can be moved between the cold storage part and the water chiller, between the cold storage part and the water cooling tower, and between the cold storage part and the air cooling tower; A first energy storage branch is connected to the chiller and the cold storage part respectively; A first driving unit, disposed in the first energy storage branch, to drive cold energy to flow from the cold storage unit to the chiller via the first energy storage branch; A second energy storage branch is connected to the chiller and the cold storage part respectively, so as to transfer cold energy from the chiller to the cold storage part; A first liquid storage chamber is provided in the water cooling tower to store circulating water cooled by the water cooling tower; A first cooling branch is connected to the first liquid storage chamber and the cooling storage part respectively; a second cooling branch, connected to the first liquid storage chamber and the first energy storage branch respectively, so that the cooling capacity of the water cooling tower can be transferred to the chiller through the second cooling branch and the first energy storage branch in sequence, so that the cooling water obtains a part of the cooling capacity from the water cooling tower and another part of the cooling capacity from the chiller; The second cooling branch is in communication with a portion of the first energy storage branch located on an upstream side of the first driving unit, so that the first driving unit can provide power for cooling energy to flow from the second cooling branch to the first energy storage branch; A third cooling branch is connected to the first liquid storage chamber and the air cooling tower respectively; A second driving unit is provided in the third cooling branch to drive the cooling capacity in the third cooling branch to flow to the air cooling tower; a fourth cooling branch connecting the second energy storage branch with a portion of the third cooling branch located on an upstream side of the second driving unit; A first control valve is provided in the first energy storage branch to control the amount of cold flowing from the cold storage part to the chiller; A second control valve is provided in the second cooling branch to control the cooling amount flowing from the first liquid storage chamber to the chiller; a third control valve, arranged in the fourth cooling branch, to control the cooling capacity of the chiller flowing to the air cooling tower; a fourth control valve, arranged in the second energy storage branch, to control the amount of cold water flowing from the chiller to the cold storage part; a fifth control valve, disposed in the third cooling branch, to control the cooling amount flowing from the first liquid storage chamber to the air cooling tower; The cold storage part further includes a storage window, so that cold energy can be stored in and taken out of the cold storage part through the storage window; The cold storage part is a liquid storage container with heat preservation function; The precooling system further comprises a liquid level detection unit and a second temperature detection unit, wherein the liquid level detection unit and the second temperature detection unit are both arranged in the liquid storage container; System working condition 1: under the premise that the equipment load of the chiller meets the working condition of 45-75%, when the chiller can meet the cooling demand of the air cooling tower, at this time, the third control valve is opened and the second control valve is closed, so that the chiller supplies cooling to the air cooling tower; If the chiller still has residual cooling capacity, the fourth control valve is opened so that the residual cooling capacity is transferred to the cold storage part for storage via the second energy storage branch; System working condition 2: when the cold storage part has sufficient cold capacity, and the system requires the chiller to operate at a working condition lower than 45% of the equipment load, the chiller is kept operating at an optimal working condition, that is, the equipment load meets the working condition of 45-75%, and the fourth control valve is opened to transfer the remaining cold capacity to the cold storage part for storage via the second energy storage branch; Alternatively, at this time, the water chiller is turned off, and the first control valve and the third control valve are opened, so that the cold storage part directly supplies cold to the air cooling tower; System operating condition three: when the cooling capacity in the cold storage part is insufficient and the system requires the chiller to operate at a condition lower than 45% of the equipment load, the chiller is kept operating at the optimal condition, and the third control valve and the fourth control valve are opened, so that the chiller supplies cooling to the air cooling tower while the remaining cooling capacity is transferred to the cold storage part for storage via the second energy storage branch; System operating condition 4: when the cold box has sufficient cooling capacity and the system requires the chiller to operate at a condition higher than 75% of the equipment load, the equipment load of the chiller is maintained at 75%, the first control valve and the third control valve are opened, and the cooling capacity stored in the cold storage unit is used to compensate for the insufficient cooling of the chiller; System operating condition 5: When the cooling capacity in the cold box is insufficient and the entire system requires the chiller to operate at a condition higher than 75% of the equipment load, the load of the chiller is reduced by adding cooling capacity to the cold storage part through the storage window, or by opening the second control valve and / or the fifth control valve; Abnormal working conditions: When the chiller is damaged or the air-cooling tower is damaged, cold energy is delivered to the cold storage part through the self-storage window.

2. The precooling system according to claim 1, characterized in that: It also includes a circulating water inflow pipeline and a dirty nitrogen pipeline, and the circulating water inflow pipeline and the dirty nitrogen pipeline are both connected to the water cooling tower; When the water cooling tower is in use, the circulating water inflow pipeline is located above the dirty nitrogen pipeline in the direction of gravity, and the first liquid storage chamber is located below the dirty nitrogen pipeline in the direction of gravity.

3. The precooling system according to claim 2, characterized in that: The dirty nitrogen pipeline comprises: A flow monitoring unit for detecting the gas flow in the contaminated nitrogen pipeline; The first temperature detection unit is used to detect the temperature of the gas in the dirty nitrogen pipeline.

4. The precooling system according to claim 1, characterized in that: It also includes a process gas inlet pipeline, a process gas outflow pipeline and a circulating water outflow pipeline, wherein the process gas inlet pipeline, the process gas outflow pipeline and the circulating water outflow pipeline are all connected to the air cooling tower; The air cooling tower further comprises a second liquid storage chamber, wherein the second liquid storage chamber is arranged at the bottom of the air cooling tower; The circulating water outflow pipeline is in communication with the second liquid storage chamber; When the water cooling tower is in use, the process gas outflow pipeline is located above the third cooling branch in the direction of gravity, and the process gas inflow pipeline is located below the third cooling branch in the direction of gravity.

5. An air separation device, characterized in that: A precooling system comprising the precooling system according to any one of claims 1 to 4.

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