Circulating water system applied to air separation system

Abstract

The utility model discloses a circulating water system applied to an air separation system. The circulating water system comprises a cooler, a residual liquid tank, an air cooling tower, a water cooling unit and a water cooling tower, a heating medium outlet of the cooler is connected with a heating medium inlet of the residual liquid tank; a refrigerant inlet of the cooler is connected with a waste nitrogen outlet of the fractionating tower; a heating medium outlet of the residual liquid tank is connected with an air inlet of the air cooling tower; the water inlet of the water cooling tower is connected with the water outlet of the air cooling tower. Compressed air is cooled in a stepped mode through the cooler, the residual liquid tank and the air cooling tower, low-temperature substances generated in other technological processes in an air separation system are adopted as cooling media, and meanwhile the temperature of circulating water is reduced through the water cooling tower by means of waste nitrogen from a fractionating tower and nitrogen. The purposes of reducing energy consumption and reducing cost are achieved on the premise that the compressed air is primarily cooled, gas can be directly exhausted into the atmosphere after heat exchange, and pollution is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of air separation systems, in particular to a circulating water system applied in air separation systems. Background Art

[0002] Air is mainly composed of nitrogen, oxygen and argon, and the purpose of separation of air separation system is to obtain these three pure gases. At present, the process flow of air separation is roughly as follows: the atmosphere enters the pre-cooling system for preliminary cooling after initial compression, and then enters the purification system to remove some impurities such as carbon dioxide, and then enters the heat exchange system for further cooling, and then enters the fractionation system for distillation, and finally enters the backup system such as product gasification, compression, and storage. At present, the process of initial cooling of compressed air generally uses a heat exchanger to use a cooling medium for heat exchange to achieve the purpose of initial cooling. The existing technical problems are high energy consumption and the emission of pollutants. It is also necessary to configure waste gas and waste liquid treatment equipment, resulting in high costs. Summary of the invention

[0003] To solve the above technical problems, the utility model provides a circulating water system for use in an air separation system. In order to have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. This summary is not a general review, nor is it intended to identify key / important components or describe the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

[0004] The utility model adopts the following technical solutions:

[0005] Provided is a circulating water system applied to an air separation system, comprising: a cooler, a residual liquid tank, an air cooling tower and a water cooling tower; the heat medium inlet of the cooler is connected to a compressed air source, the heat medium outlet of the cooler is connected to the heat medium inlet of the residual liquid tank, and the refrigerant inlet of the cooler is connected to the dirty nitrogen outlet of a fractionating tower; the refrigerant inlet of the residual liquid tank is connected to a residual liquid conveying pipe, and the heat medium outlet of the residual liquid tank is connected to the air inlet of the air cooling tower; the water inlet of the water cooling tower is connected to the water outlet of the air cooling tower, and a first air inlet and a second air inlet are arranged on the water cooling tower, the first air inlet is connected to the dirty nitrogen outlet of the fractionating tower, and the second air inlet is connected to the nitrogen outlet of the fractionating tower.

[0006] Furthermore, the circulating water system used in the air separation system also includes: a water cooling unit; the water outlet of the water cooling tower is connected to the water inlet side of the water cooling unit, and the water inlet of the air cooling tower is connected to the water outlet side of the water cooling unit.

[0007] Furthermore, the circulating water system applied to the air separation system also includes: a first water supply pipeline, a second water supply pipeline and two water pumps; the water inlet end of the first water supply pipeline is connected to the water outlet of the water cooling tower, and the two water outlet ends of the first water supply pipeline are respectively connected to the water inlets of the two water pumps; the water outlet end of the second water supply pipeline is connected to the water inlet side of the water cooling unit, and the two water inlet ends of the second water supply pipeline are respectively connected to the water outlets of the two water pumps.

[0008] Furthermore, the circulating water system used in the air separation system also includes: a water supply pipeline; the water inlet end of the water supply pipeline is connected to the water outlet side of the water cooling unit, and the water outlet end of the water supply pipeline is connected to the first water supply pipeline.

[0009] Furthermore, the refrigerant outlet of the cooler is connected to the vent air pipeline at the top of the water cooling tower.

[0010] Furthermore, the refrigerant outlet of the residual liquid tank is connected to the venting air pipeline at the top of the water cooling tower; the residual liquid delivery pipe is connected to the discharge ports of the tank truck and the liquid pump.

[0011] Furthermore, sewage pipes are provided at the bottom of the water cooling tower and the air cooling tower.

[0012] The beneficial effects brought by the utility model are as follows: the application utilizes a cooler, a residual liquid tank and an air-cooling tower to perform step-by-step cooling of the compressed air. The cooling medium adopts low-temperature substances produced by other process flows in the air separation system. At the same time, the water-cooling tower utilizes the polluted nitrogen gas and nitrogen from the distillation tower to reduce the temperature of the circulating water, thereby achieving the purpose of reducing energy consumption and reducing costs under the premise of achieving preliminary cooling of the compressed air. Moreover, the gas can be directly discharged into the atmosphere after heat exchange without pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 The utility model is a schematic diagram of a circulating water system applied to an air separation system. DETAILED DESCRIPTION

[0015] The following is a detailed description of the embodiments of the utility model in conjunction with the accompanying drawings. It should be clear that the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of 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.

[0016] like Figure 1 As shown, in some illustrative embodiments, a circulating water system applied to an air separation system is provided, comprising: a cooler 1, a residual liquid tank 2, an air cooling tower 3, a water cooling tower 4, and a water cooling unit 5.

[0017] Cooler 1 performs the first heat exchange and cooling of the compressed air, and the cooling medium used is the dirty nitrogen gas discharged from the distillation tower. The specific connection method of cooler 1 is as follows:

[0018] The heat medium inlet of the cooler 1 is connected to a compressed air source, which is a compression system in the air separation system. The compression system initially compresses the atmosphere and then sends it to the circulating water system of this embodiment for cooling;

[0019] The heat medium outlet of the cooler 1 is connected to the heat medium inlet of the residual liquid tank 2, and the compressed air after the first heat exchange and cooling in the cooler 1 is transported to the residual liquid tank 2 for further heat exchange and cooling;

[0020] The refrigerant inlet of the cooler 1 is connected to the dirty nitrogen outlet 601 of the fractionation tower 6. The cooler 1 uses the dirty nitrogen with a lower temperature discharged from the fractionation tower 6 in the air separation distillation process to cool down the air, thereby reducing energy consumption.

[0021] The refrigerant outlet of the cooler 1 is connected to the vent air pipeline 401 at the top of the water cooling tower 4. After the heat exchange is completed, the dirty nitrogen gas is directly discharged into the atmosphere through the vent air pipeline 401 without pollution.

[0022] The residual liquid tank 2 performs a second heat exchange and cooling on the compressed air. The cooling medium used is the residual liquid discharged from the tank truck and the liquid pump. The residual liquid tank 2 adopts a heat exchanger structure. The specific connection method of the residual liquid tank 2 is as follows:

[0023] The heat medium inlet of the residual liquid tank 2 is connected to the heat medium outlet of the cooler 1;

[0024] The heat medium outlet of the residual liquid tank 2 is connected to the air inlet of the air cooling tower 3, and the compressed air after the second heat exchange and cooling in the residual liquid tank 2 is transported to the air cooling tower 3 for further heat exchange and cooling;

[0025] The refrigerant inlet of the residual liquid tank 2 is connected to the residual liquid delivery pipe 701, and the residual liquid delivery pipe 701 is connected to the discharge port of the tank truck and the liquid pump, that is, the residual liquid discharged from the tank truck and the liquid pump enters the residual liquid tank 2 for heat exchange, thereby reducing energy consumption;

[0026] The refrigerant outlet of the residual liquid tank 2 is connected to the vent air pipeline 401 at the top of the water cooling tower 4. The residual liquid after the heat exchange is completed is directly discharged into the atmosphere through the vent air pipeline 401 without pollution.

[0027] The air cooling tower 3 performs the third heat exchange cooling on the compressed air, and the cooling medium used is the circulating water cooled by the water cooling tower 4 and the water cooling unit 5. The specific connection method of the air cooling tower 3 is as follows:

[0028] The air inlet of the air cooling tower 3 is connected to the heat medium outlet of the residual liquid tank 2;

[0029] The air outlet of the air cooling tower 3 is connected to the purification system 8 in the air separation system, that is, the compressed air after preliminary cooling in this embodiment is sent to the purification system for purification process;

[0030] The water outlet of the air cooling tower 3 is connected to the water inlet of the water cooling tower 4, that is, the circulating water used to cool the compressed air in the air cooling tower 3 is transported to the water cooling tower 4 for cooling after the temperature is increased by heat exchange, so as to carry out the next cycle of heat exchange;

[0031] The water inlet of the air cooling tower 3 is connected to the water outlet side of the water cooling unit 5 .

[0032] The water cooling tower 4 is used for preliminary cooling of the circulating water, and the water cooling unit 5 is used for secondary cooling of the circulating water and as a circulating power to ensure that the air cooling tower 3 has sufficient low-temperature circulating water to cool the compressed air. The specific connection method between the water cooling tower 4 and the water cooling unit 5 is described below.

[0033] The water cooling tower 4 is provided with a first air inlet 402 and a second air inlet 403 .

[0034] The first air inlet 402 is connected to the dirty nitrogen outlet 601 of the fractionation tower 6, that is, the dirty nitrogen discharged from the fractionation tower 6 is divided into two paths, one of which enters the cooler 1 for heat exchange, and the other enters the water cooling tower 4 to cool the circulating water from the air cooling tower 3.

[0035] The second air inlet 403 is connected to the nitrogen outlet 602 of the distillation tower 6, that is, the nitrogen discharged from the distillation tower 6 enters the water cooling tower 4 to cool the circulating water from the air cooling tower 3, thereby ensuring the cooling effect and utilizing the existing energy for cooling, which can reduce the system energy consumption to a certain extent.

[0036] The water outlet of the water cooling tower 4 is connected to the water inlet side of the water cooling unit 5, and the water inlet of the air cooling tower 3 is connected to the water outlet side of the water cooling unit 5. The water cooling unit 5 sends the cooled circulating water into the air cooling tower 3 to cool the compressed air.

[0037] The bottoms of the air cooling tower 3 and the water cooling tower 4 are both provided with sewage pipes for immediate sewage discharge.

[0038] The circulating water system of this embodiment further includes: a water supply pipeline 10 , a first water supply pipeline 11 , a second water supply pipeline 12 and two water pumps 13 .

[0039] The water inlet end of the first water pipeline 11 is connected to the water outlet of the water cooling tower 4, and the two water outlet ends of the first water pipeline 11 are respectively connected to the water inlets of two water pumps 13; the water outlet end of the second water pipeline 12 is connected to the water inlet side of the water cooling unit 5, and the two water inlet ends of the second water pipeline 12 are respectively connected to the water outlets of the two water pumps 13. The circulating water discharged from the water cooling tower 4 is sent to the water cooling unit 5 by the two water pumps 13 through the first water pipeline 11 and the second water pipeline 12 to ensure the dynamic stability of the water circulation.

[0040] The water inlet end of the water supply pipeline 10 is connected to the water outlet side of the water cooling unit 5, and the water outlet end of the water supply pipeline 10 is connected to the first water supply pipeline 11 to prevent water shortage.

[0041] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A circulating water system used in an air separation system, characterized in that: include: Coolers, residual liquid tanks, air cooling towers and water cooling towers; The heat medium inlet of the cooler is connected to the compressed air source, the heat medium outlet of the cooler is connected to the heat medium inlet of the residual liquid tank, and the refrigerant inlet of the cooler is connected to the dirty nitrogen outlet of the fractionation tower; The refrigerant inlet of the residual liquid tank is connected to the residual liquid delivery pipe, and the heat medium outlet of the residual liquid tank is connected to the air inlet of the air cooling tower; The water inlet of the water cooling tower is connected to the water outlet of the air cooling tower. The water cooling tower is provided with a first air inlet and a second air inlet. The first air inlet is connected to the dirty nitrogen outlet of the fractionation tower, and the second air inlet is connected to the nitrogen outlet of the fractionation tower.

2. A circulating water system used in an air separation system according to claim 1, characterized in that: Also includes: The water outlet of the water cooling tower is connected to the water inlet side of the water cooling unit, and the water inlet of the air cooling tower is connected to the water outlet side of the water cooling unit.

3. A circulating water system used in an air separation system according to claim 2, characterized in that: Also includes: A first water delivery pipeline, a second water delivery pipeline and two water pumps; The water inlet end of the first water pipeline is connected to the water outlet of the water cooling tower, and the two water outlet ends of the first water pipeline are respectively connected to the water inlets of the two water pumps; The water outlet end of the second water supply pipeline is connected to the water inlet side of the water cooling unit, and the two water inlet ends of the second water supply pipeline are respectively connected to the water outlets of the two water pumps.

4. A circulating water system used in an air separation system according to claim 3, characterized in that: Also includes: Water supply pipeline; The water inlet end of the water supply pipeline is connected to the water outlet side of the water cooling unit, and the water outlet end of the water supply pipeline is connected to the first water supply pipeline.

5. A circulating water system used in an air separation system according to claim 4, characterized in that: The refrigerant outlet of the cooler is connected to the vent air pipeline at the top of the water cooling tower.

6. A circulating water system used in an air separation system according to claim 5, characterized in that: The refrigerant outlet of the residual liquid tank is connected to the venting air pipeline at the top of the water cooling tower; the residual liquid delivery pipe is connected to the discharge ports of the tank truck and the liquid pump.

7. A circulating water system used in an air separation system according to claim 6, characterized in that: The bottoms of the water cooling tower and the air cooling tower are both provided with sewage pipes.

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