Waste cold recycling system of air separation tower

Abstract

The utility model discloses a waste cold recycling system of an air separation tower, which comprises at least one liquid storage tank connected with the air separation tower through at least one input pipeline and at least one output pipeline; the at least one input control valve is mounted on the at least one input pipeline; the at least one output control valve is mounted on the at least one output pipeline; wherein in an abnormal state of the air separation tower, a liquid product in the air separation tower is input into the liquid storage tank through the input pipeline to be stored as a waste cold product; and in the process that the air separation tower is switched from the shutdown state to the driving state, waste cold products in the liquid storage tank are input into the air separation tower through the output pipeline. According to the utility model, the waste cold products can be recycled in the abnormal state of the air separation tower, and the waste cold products are utilized to cool the air separation tower in the process of switching the air separation tower from the parking state to the driving state, so that the time for the air separation tower to reach the normal working condition after driving can be shortened, the waste cold products are utilized, and the energy consumption is reduced. And the requirements of energy conservation and emission reduction are met.

Description

Technical Field

[0001] The utility model relates to the technical field of air separation, in particular to an air separation tower waste cold recovery and utilization system. Background Art

[0002] Air separation equipment is a cryogenic equipment that liquefies air through artificial refrigeration and obtains high-purity liquid oxygen, liquid nitrogen and liquid argon after separation. As a device that is strongly related to most traditional industries and emerging industries such as chemical industry and metallurgy, air separation equipment is constantly undergoing technological iterations as the downstream demand side changes in gas requirements. In order to save energy and reduce emissions, new demands have been made for air separation equipment and other gas separation equipment. Users have higher requirements for the technical requirements, energy consumption, reliability, delivery cycle, etc. of air separation equipment. It is far from enough to just meet the oxygen output.

[0003] Because most of the existing large-scale air separation equipment separates gases by cryogenic method, it takes a long time and consumes a lot of energy to start the equipment up and reach normal operating conditions. In addition, when the air separation tower is unstable, liquid oxygen and liquid nitrogen with substandard purity are produced, which is "waste cold". There is no appropriate way to deal with it, and the generated cold source is wasted, which does not meet the requirements of energy conservation and emission reduction. Utility Model Content

[0004] The utility model aims to provide an air separation tower waste cold recovery system to solve the current technical problem that when the concentration of liquid products does not meet the requirements due to abnormal operation of the air separation tower, the liquid products with concentrations not meeting the requirements are discharged as waste liquid, resulting in the waste of cold of this part of the liquid products.

[0005] The above-mentioned purpose of the utility model can be achieved by adopting the following technical solutions:

[0006] The utility model provides an air separation tower waste cold recovery and utilization system, comprising: at least one liquid storage tank, which is connected to the air separation tower through at least one input pipeline and at least one output pipeline to form at least one waste cold recovery and utilization loop; at least one input control valve, which is installed on the input pipeline of at least one waste cold recovery and utilization loop; at least one output control valve, which is installed on the output pipeline of at least one waste cold recovery and utilization loop; wherein, the liquid storage tank has a recovery state and a cooling state; in the recovery state, the input control valve is in an open state, and the liquid product in the air separation tower is input into the liquid storage tank through the input pipeline and stored as a waste cold product; in the cooling state, the output control valve is in an open state, and the waste cold product in the liquid storage tank is input into the air separation tower through the output pipeline.

[0007] In an embodiment of the utility model, the liquid storage tank is in the recovery state when the air separation tower is in an abnormal state; the liquid storage tank is in the cooling state when the air separation tower is switched from a shutdown state to a startup state.

[0008] In an embodiment of the utility model, the number of the liquid storage tanks is multiple and they are connected to the air separation tower through multiple input pipelines and multiple output pipelines to form multiple waste cold recovery loops, and the multiple waste cold recovery loops are arranged from top to bottom.

[0009] In an embodiment of the utility model, the air separation tower includes an upper tower and a lower tower arranged up and down, the multiple liquid storage tanks include at least one first liquid storage tank and at least one second liquid storage tank, the multiple waste cold recovery loops include at least one first waste cold recovery loop and at least one second waste cold recovery loop, at least one first liquid storage tank is connected to the upper tower through a first input pipeline and a first output pipeline to form at least one first waste cold recovery loop, and at least one second liquid storage tank is connected to the lower tower through a second input pipeline and a second output pipeline to form at least one second waste cold recovery loop.

[0010] In an embodiment of the utility model, the liquid product includes liquid oxygen in the upper tower and liquid nitrogen in the lower tower; in the recovery state, the liquid oxygen in the upper tower can be transported to the first liquid storage tank and stored as a liquid oxygen waste cooling product, and the liquid nitrogen in the lower tower can be transported to the second liquid storage tank and stored as a liquid nitrogen waste cooling product.

[0011] In an embodiment of the utility model, the recovery state includes a first recovery state and a second recovery state; in the first recovery state, the input control valve on the first input pipeline is in an open state, and the output control valve on the first output pipeline is in a closed state, so that the liquid oxygen in the upper tower can be transported to the first liquid storage tank for storage as a liquid oxygen waste cooling product, and the input control valve on the second input pipeline and the output control valve on the second output pipeline are both in a closed state; in the second recovery state, the liquid air flow in the air separation tower is greater than a preset flow and the first liquid storage tank is in a full state, the input control valve on the first input pipeline and the output control valve on the first output pipeline are both in an open state, so that the liquid oxygen waste cooling product circulates in the first waste cooling recovery and utilization loop, the input control valve on the second input pipeline is in an open state, and the output control valve on the second output pipeline is in a closed state, so that the liquid nitrogen in the lower tower is output to the second liquid storage tank for storage as a liquid nitrogen waste cooling product.

[0012] In an embodiment of the utility model, a liquid oxygen outlet is provided at the bottom of the upper tower, and the input end of the input pipeline of the first waste cold recovery circuit is arranged close to the liquid oxygen outlet; the output end of the output pipeline of the first waste cold recovery circuit is arranged close to the top of the upper tower.

[0013] In an embodiment of the utility model, the lower tower is provided with a liquid nitrogen output port, the input end of the input pipeline of the second waste cold recovery circuit is arranged close to the liquid nitrogen output port; the output end of the output pipeline of the second waste cold recovery circuit is located below the liquid nitrogen output port.

[0014] In an embodiment of the utility model, the output end of the input pipeline is located at the top of the liquid storage tank, the input end of the output pipeline of the waste cold recovery loop is located at the bottom of the liquid storage tank, and a low-temperature pumping structure is installed on the output pipeline.

[0015] In an embodiment of the utility model, the air separation tower waste cold recovery and utilization system further comprises an air separation cold box, and the air separation tower and the liquid storage tank are both installed in the air separation cold box.

[0016] In the implementation manner of the utility model, the liquid storage tank is coated with a heat-insulating layer.

[0017] The characteristics and advantages of this utility model are:

[0018] The waste cold recycling system of an air separation tower of the utility model is connected with the air separation tower through an input pipeline and an output pipeline to form a waste cold recycling loop, and the input pipeline is controlled by an input control valve installed on the input pipeline to open and close the input pipeline, and the output pipeline is controlled by an output control valve installed on the output pipeline to open and close the output pipeline, so that the liquid storage tank can be controlled to form a recycling state under the abnormal state (i.e., unstable state) of the air separation tower, so that the liquid product in the air separation tower is input into the liquid storage tank through the input pipeline and stored as a waste cold product, thereby realizing the recycling of the waste cold product, and the liquid storage tank is controlled to form a cooling state in the process of switching the air separation tower from a parking state to a starting state, and the waste cold product is provided to the air separation tower through the output pipeline, and the air separation tower is cooled by the waste cold product, so that the time for the air separation tower to reach a normal working condition after starting can be shortened, and the waste cold product can be utilized, which meets the requirements of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a structural schematic diagram of the waste cold recovery and utilization system of the hollow tower of the utility model.

[0021] Figure 2 The utility model is a usage state diagram of the waste cold recovery and utilization system of the hollow separation tower when the air separation tower is in an abnormal state.

[0022] Figure 3 This is another usage state diagram of the hollow tower waste cold recovery and utilization system of the utility model when the air separation tower is in an abnormal state.

[0023] Figure 4 The utility model is a usage status diagram of the waste cold recovery and utilization system of the hollow separation tower during the process of switching the air separation tower from the shutdown state to the start-up state.

[0024] In the figure:

[0025] 1. Air separation tower; 11. Upper tower; 12. Lower tower; 13. Heat exchanger;

[0026] 2. Liquid storage tank; 21. First liquid storage tank; 22. Second liquid storage tank;

[0027] 3. Input pipeline; 31. First input pipeline; 32. Second input pipeline;

[0028] 4. output pipeline; 41. first output pipeline; 42. second output pipeline;

[0029] 5. Input control valve; 51. First input control valve; 52. Second input control valve;

[0030] 6. Output control valve; 61. First output control valve; 62. Second output control valve;

[0031] 7. Cryogenic pumping structure; 71. First cryogenic pumping structure; 72. Second cryogenic pumping structure. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] like Figure 1As shown, the utility model provides an air separation tower waste cold recovery system, comprising: at least one liquid storage tank 2, which is connected to the air separation tower 1 through at least one input pipeline 3 and at least one output pipeline 4 to form at least one waste cold recovery loop; at least one input control valve 5, installed on the input pipeline 3 of the at least one waste cold recovery loop; at least one output control valve 6, installed on the output pipeline 4 of the at least one waste cold recovery loop; wherein, Figure 2 and Figure 3 As shown, the liquid storage tank 2 can form a recovery state when the air separation tower 1 is in an abnormal state. In the recovery state, the input control valve 5 is in an open state, and the liquid product in the air separation tower 1 is input into the liquid storage tank 2 through the input pipeline 3 and stored as a waste cold product; Figure 4 As shown, the liquid storage tank 2 forms a cooling state during the process of switching the air separation tower 1 from the shutdown state to the start-up state. In the cooling state, the output control valve 6 is in an open state, and the waste cooling product in the liquid storage tank 2 is input into the air separation tower 1 through the output pipeline 4.

[0034] The waste cold recycling system of an air separation tower of the utility model is connected with an air separation tower 1 through an input pipeline 3 and an output pipeline 4 to form a waste cold recycling loop, and controls the on-off of the input pipeline 3 through an input control valve 5 installed on the input pipeline 3 and controls the on-off of the output pipeline 4 through an output control valve 6 installed on the output pipeline 4, so that the liquid storage tank 2 can be controlled to form a recycling state under an abnormal state (i.e., an unstable state) of the air separation tower 1, so that the liquid product in the air separation tower 1 is input into the liquid storage tank 2 through the input pipeline 3 and stored as a waste cold product, thereby realizing the recycling of the waste cold product, and controlling the liquid storage tank 2 to form a cooling state during the process of switching the air separation tower 1 from a parking state to a starting state, and providing the waste cold product to the air separation tower 1 through the output pipeline 4, and utilizing the waste cold product to cool the air separation tower 1, thereby shortening the time for the air separation tower 1 to reach a normal working condition after starting, realizing the utilization of the waste cold product, and meeting the requirements of energy conservation and emission reduction.

[0035] The working process of the air separation tower waste cold recovery and utilization system of the utility model comprises the following steps: when the air separation tower 1 is in an abnormal state, the air separation tower 1 stops outputting liquid products to the outside, and outputs the liquid products in the air separation tower 1 to at least one liquid storage tank 2 for storage as waste cold products; until the air separation tower 1 recovers from the abnormal state to the normal state, the liquid products are stopped from being input into the liquid storage tank 2, and the air separation tower 1 outputs the liquid products to the outside; during the process of the air separation tower 1 switching from the shutdown state to the start-up state, the waste cold products in the liquid storage tank 2 are input into the air separation tower 1 for cooling.

[0036] Among them, the abnormal state of the air separation tower 1 refers to the state of unstable operation of the air separation tower 1. It can be judged whether the air separation tower 1 is in an abnormal state according to the operating parameters of the air separation tower 1, for example, the fluctuation of a certain operating parameter of the air separation tower 1 does not meet the requirements; it can also be judged whether the air separation tower 1 is in an abnormal state according to the concentration of the liquid product output by the air separation tower 1, for example, the concentration of the liquid product output by the air separation tower 1 is reduced.

[0037] like Figure 1 As shown, in an embodiment of the utility model, there are multiple liquid storage tanks 2 and they are connected to the air separation tower 1 through multiple input pipelines 3 and multiple output pipelines 4 to form multiple waste cold recovery loops, and the multiple waste cold recovery loops are arranged from top to bottom.

[0038] Specifically, the air separation tower 1 includes an upper tower 11 and a lower tower 12 arranged up and down, a heat exchanger 13 is provided between the upper tower 11 and the lower tower 12, the upper tower 11 is provided with a liquid air reflux port for liquid air to flow in, a liquid oxygen outlet port for liquid oxygen to flow out, a liquid nitrogen reflux port for liquid nitrogen to flow in, a dirty liquid nitrogen outlet port for dirty liquid nitrogen to flow out, and a nitrogen outlet port for nitrogen product to flow out, and the lower tower 12 is provided with a liquid nitrogen outlet port for liquid nitrogen to flow out, an air input port for air to flow in, and a liquid air outlet port for liquid air to flow out. The air input port of the lower tower 12 is connected to an air input pipeline, the liquid air reflux port of the upper tower 11 and the liquid air output port of the lower tower 12 are connected through a liquid air reflux pipeline, the liquid nitrogen reflux port of the upper tower 11 and the liquid nitrogen output port of the lower tower 12 are connected through a liquid nitrogen reflux pipeline, the dirty liquid nitrogen output port of the upper tower 11 is connected to the dirty liquid nitrogen output pipeline, the nitrogen output port of the upper tower 11 is connected to the nitrogen output pipeline, and the liquid oxygen output port of the upper tower 11 is connected to the liquid oxygen output pipeline. The liquid in the lower tower 12 enters the upper tower 11 for distillation under the differential pressure between the upper tower 11 and the lower tower 12, and the nitrogen rising in the lower tower 12 exchanges heat with the liquid nitrogen in the upper tower 11 in the heat exchanger 13, so that the nitrogen rising in the lower tower 12 is condensed into liquid nitrogen in the heat exchanger 13, and the liquid nitrogen in the upper tower 11 flows downward into the heat exchanger 13 and evaporates into nitrogen. The more specific structure and working principle of the air separation tower 1 can be referred to the prior art and will not be described in detail here. Figure 1 As shown, in order to avoid the loss of cold of the waste cold product in the liquid storage tank 2, the air separation tower waste cold recovery system also includes an air separation cold box, and the air separation tower 1 and the liquid storage tank 2 are both installed in the air separation cold box. In addition, the liquid storage tank 2 is coated with an insulation layer. The insulation layer includes an insulation shell sleeved on the outside of the liquid storage tank 2 and an insulation filler layer formed by filling the gap space between the insulation shell and the liquid storage tank 2 with insulation materials.

[0039] like Figure 1As shown, the output end of the input pipeline 3 is located at the top of the liquid storage tank 2, the input end of the output pipeline 4 is located at the bottom of the liquid storage tank 2, and a low-temperature pumping structure 7 is installed on the output pipeline 4. The low-temperature pumping structure 7 provides a conveying power for the output of the waste cold product in the liquid storage tank 2. In this embodiment, the material of the liquid storage tank 2 is electropolished stainless steel; the flow rate of the low-temperature pumping structure 7 is 5m 3 / min.

[0040] like Figure 1 As shown, in the embodiment of the utility model, the plurality of liquid storage tanks 2 include at least one first liquid storage tank 21 and at least one second liquid storage tank 22, the plurality of waste cold recovery loops include at least one first waste cold recovery loop and at least one second waste cold recovery loop, at least one first liquid storage tank 21 is connected to the upper tower 11 to form at least one first waste cold recovery loop, and at least one second liquid storage tank 22 is connected to the lower tower 12 to form at least one second waste cold recovery loop. The first waste cold recovery pipeline and the second waste cold recovery pipeline are provided to respectively realize the recycling of the liquid product in the upper tower 11 and the liquid product in the lower tower 12. Among them, when the air separation tower 1 is in an abnormal state, the liquid product in the upper tower 11 is mainly liquid oxygen whose concentration does not meet the requirements, and the liquid product in the lower tower 12 is mainly liquid oxygen whose concentration does not meet the requirements.

[0041] Specifically, a liquid oxygen outlet is provided at the bottom of the upper tower 11, and the input end of the input pipeline 3 (defined as the first input pipeline 31) of the first waste cold recovery and utilization loop is arranged near the liquid oxygen outlet, so that the liquid flowing into the first input pipeline 31 of the upper tower 11 and the liquid flowing out of the liquid oxygen outlet in the upper tower 11 have substantially the same composition, that is, the liquid oxygen output by the upper tower 11 in an abnormal state of the air separation tower 1. A liquid nitrogen outlet is provided at the lower tower 12, and the input end of the input pipeline 3 of the second waste cold recovery and utilization loop is arranged near the liquid nitrogen outlet, so that the liquid flowing into the second input pipeline 32 of the lower tower 12 and the liquid flowing out of the liquid nitrogen outlet in the lower tower 12 have substantially the same composition, that is, the liquid nitrogen output by the lower tower 12 in an abnormal state of the air separation tower 1. The output end of the output pipeline 4 (defined as the first output pipeline 41) of the first waste cold recovery and utilization loop is arranged near the top of the upper tower 11. The output end of the output pipeline 4 (defined as the second output pipeline 42) of the second waste cold recovery and utilization loop is located below the liquid nitrogen outlet. The first liquid storage tank 21 is disposed substantially at the same height as the middle of the upper tower 11 , and the second liquid storage tank 22 is disposed substantially at the same height as the middle of the lower tower 12 .

[0042] like Figure 1As shown, the output end of the first input pipeline 31 is located at the top of the first liquid storage tank 21, the input end of the first input pipeline 31 is located at the bottom of the first liquid storage tank 21, and the first output pipeline 41 is installed with a first low-temperature pumping structure 71; the output end of the second output pipeline 42 is located at the top of the second liquid storage tank 22, the input end of the second input pipeline 32 is located at the bottom of the second liquid storage tank 22, and the second output pipeline 42 is installed with a second low-temperature pumping structure 72. The first input pipeline 31 is installed with a first input control valve 51, and the first output pipeline 41 is installed with a first output control valve 61; the second input pipeline 32 is installed with a second input control valve 52, and the first output pipeline 41 is installed with a second output control valve 62.

[0043] In the recovery state, the liquid oxygen in the air separation tower 1 is transported to the first liquid storage tank 21 and stored as a liquid oxygen waste cooling product; the liquid nitrogen in the air separation tower 1 is transported to the second liquid storage tank 22 and stored as a liquid nitrogen waste cooling product. The liquid oxygen and liquid nitrogen in the air separation tower 1 are recovered separately by setting the first liquid storage tank 21 and the second liquid storage tank 22.

[0044] like Figure 2 and Figure 3 As shown, in some embodiments of the utility model, when the air separation tower 1 is in an abnormal state, a first recovery state is first formed, and the liquid oxygen in the air separation tower 1 is output to the first liquid storage tank 21 for storage as a liquid oxygen waste cooling product; when the liquid air flow rate input into the air separation tower 1 is greater than the preset flow rate and the first liquid storage tank 21 is full, a second recovery state is formed, and the first liquid storage tank 21 is connected to the air separation tower 1 to form a first waste cooling recovery loop, so that the liquid oxygen waste cooling product circulates in the first waste cooling recovery loop, and the liquid nitrogen in the air separation tower 1 is output to the second liquid storage tank 22 for storage as a liquid nitrogen waste cooling product.

[0045] Specifically, when the air separation tower 1 is in an abnormal state, the concentration of liquid oxygen flowing out of the liquid oxygen outlet in the upper tower 11 is reduced, so the liquid oxygen output control valve 6 on the liquid oxygen output pipeline 4 is closed, so that the liquid oxygen in the upper tower 11 no longer flows out, and the air separation tower waste cold recovery and utilization system enters the first recovery stage, such as Figure 2 As shown, the first output control valve 61 and the second output control valve 62 are both kept in a closed state, and the first input control valve 51 is opened, so that the liquid oxygen in the upper tower 11 flows into the first liquid storage tank 21 through the first input pipeline 31 and is stored as a liquid oxygen waste cold product; when the first liquid storage tank 21 is full and the liquid air flow rate input into the upper tower 11 is still greater than the preset flow rate, the air separation tower waste cold recovery and utilization system enters the second recovery stage, such as Figure 3As shown, the first output control valve 61 and the second input control valve 52 are opened, so that the liquid oxygen waste cooling product circulates in the first waste cooling recovery and utilization loop, and the liquid nitrogen in the lower tower 12 flows into the second liquid storage tank 22 through the second input pipeline 32 and is stored as a liquid nitrogen waste cooling product until the air separation tower 1 is stabilized (i.e., restored to a normal state), and the first input control valve 51, the second input control valve 52 and the first output control valve 61 are closed; and then the liquid oxygen output control valve on the liquid oxygen output pipeline is reopened, so that the liquid oxygen in the upper tower 11 flows out through the liquid oxygen output pipeline. In a specific embodiment of the utility model, the first recovery stage lasts for about 10 minutes, and the second recovery stage lasts for about 5 minutes.

[0046] In some other embodiments of the present invention, when the air separation tower 1 is in an abnormal state, the first liquid storage tank 21 can recover liquid oxygen and the second liquid storage tank 22 can recover liquid nitrogen at the same time.

[0047] Specifically, when the air separation tower 1 is in an abnormal state, the first output control valve 61 and the second output control valve 62 are both kept in a closed state, and the first input control valve 51 and the second input control valve 52 are opened, so that the liquid oxygen in the upper tower 11 flows into the first liquid storage tank 21 through the first input pipeline 31 and is stored as a liquid oxygen waste cooling product, and the liquid nitrogen in the lower tower 12 flows into the second liquid storage tank 22 through the second input pipeline 32 and is stored as a liquid nitrogen waste cooling product, until the air separation tower 1 is stabilized (i.e., restored to a normal state), and the first input control valve 51 and the second input control valve 52 are closed; therefore, when the air separation tower 1 is in a subsequent normal production state, the liquid oxygen waste cooling product is stored in the first liquid storage tank 21, and the liquid nitrogen waste cooling product is stored in the second liquid storage tank 22.

[0048] like Figure 4 As shown, when the air separation tower 1 is switched from a shutdown state (shutdown due to overhaul, maintenance or other reasons) to a startup state (restarting due to completion of overhaul, maintenance or other reasons), the first output control valve 61 and the second output control valve 62 are opened and the first cryogenic pump structure and the second cryogenic pump structure are started, and the liquid oxygen waste cooling product is transported from the first output pipeline 41 to the upper tower 11 to cool the upper tower 11, and the liquid nitrogen waste cooling product is transported from the second output pipeline 42 to the lower tower 12 to cool the lower tower 12.

[0049] The above are only several embodiments of the present invention. Those skilled in the art can make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. An air separation tower waste cooling recovery and utilization system, characterized in that: include: At least one liquid storage tank connected to the air separation tower via at least one input pipeline and at least one output pipeline to form at least one waste cold recovery loop; At least one input control valve installed on the input pipeline of at least one of the waste cooling recovery circuits; At least one output control valve installed on the output pipeline of at least one of the waste cooling recovery circuits; Wherein, the liquid storage tank has a recovery state and a cooling state; In the recovery state, the input control valve is in an open state, and the liquid product in the air separation tower is input into the liquid storage tank through the input pipeline and stored as a waste cooling product; In the cooling state, the output control valve is in an open state, and the waste cooling product in the liquid storage tank is input into the air separation tower through the output pipeline.

2. The air separation tower waste cold recovery and utilization system according to claim 1, characterized in that: There are multiple liquid storage tanks, which are connected to the air separation tower via multiple input pipelines and multiple output pipelines to form multiple waste cold recovery loops, and the multiple waste cold recovery loops are arranged from top to bottom.

3. The air separation tower waste cold recovery and utilization system according to claim 2, characterized in that: The air separation tower includes an upper tower and a lower tower arranged up and down, the multiple liquid storage tanks include at least one first liquid storage tank and at least one second liquid storage tank, the multiple waste cold recovery loops include at least one first waste cold recovery loop and at least one second waste cold recovery loop, at least one first liquid storage tank is connected to the upper tower through a first input pipeline and a first output pipeline to form at least one first waste cold recovery loop, and at least one second liquid storage tank is connected to the lower tower through a second input pipeline and a second output pipeline to form at least one second waste cold recovery loop.

4. The air separation tower waste cold recovery and utilization system according to claim 3, characterized in that: The liquid product includes liquid oxygen in the upper tower and liquid nitrogen in the lower tower; In the recovery state, the liquid oxygen in the upper tower can be transported to the first liquid storage tank and stored as a liquid oxygen waste cooling product, and the liquid nitrogen in the lower tower can be transported to the second liquid storage tank and stored as a liquid nitrogen waste cooling product.

5. The air separation tower waste cold recovery and utilization system according to claim 4, characterized in that: The recycling state includes a first recycling state and a second recycling state; In the first recovery state, the input control valve on the first input pipeline is in an open state, and the output control valve on the first output pipeline is in a closed state, so that the liquid oxygen in the upper tower can be transported to the first liquid storage tank for storage as a liquid oxygen waste cooling product, and the input control valve on the second input pipeline and the output control valve on the second output pipeline are both in a closed state; In the second recovery state, the liquid air flow rate in the air separation tower is greater than the preset flow rate and the first liquid storage tank is full, the input control valve on the first input pipeline and the output control valve on the first output pipeline are both in the open state, so that the liquid oxygen waste cooling product circulates in the first waste cooling recovery and utilization loop, the input control valve on the second input pipeline is in the open state, and the output control valve on the second output pipeline is in the closed state, so that the liquid nitrogen in the lower tower is output to the second liquid storage tank for storage as a liquid nitrogen waste cooling product.

6. The air separation tower waste cold recovery and utilization system according to claim 3, characterized in that: A liquid oxygen outlet is provided at the bottom of the upper tower, and an input end of the input pipeline of the first waste cold recovery loop is arranged close to the liquid oxygen outlet; an output end of the output pipeline of the first waste cold recovery loop is arranged close to the top of the upper tower.

7. The air separation tower waste cold recovery and utilization system according to claim 3, characterized in that: The lower tower is provided with a liquid nitrogen output port, and the input end of the input pipeline of the second waste cold recovery circuit is arranged close to the liquid nitrogen output port; the output end of the output pipeline of the second waste cold recovery circuit is located below the liquid nitrogen output port.

8. The air separation tower waste cold recovery and utilization system according to claim 1, characterized in that: The output end of the input pipeline is located at the top of the liquid storage tank, the input end of the output pipeline of the waste cold recovery loop is located at the bottom of the liquid storage tank, and a low-temperature pumping structure is installed on the output pipeline.

9. The air separation tower waste cold recovery and utilization system according to claim 1, characterized in that: The air separation tower waste cold recovery and utilization system also includes an air separation cold box, and the air separation tower and the liquid storage tank are both installed in the air separation cold box.

10. The air separation tower waste cold recovery and utilization system according to claim 1, characterized in that: The liquid storage tank is coated with a heat-insulating layer.

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