Air separation energy-saving refrigerating system

Abstract

The utility model provides an air separation energy-saving refrigerating system, which relates to the technical field of air separation systems and comprises an air compression system, a first heat exchanger, a water cooler, a bromine cooler and an air cooling tower, an air outlet of the air compression system is communicated with a heat source inlet of the first heat exchanger, and a heat source outlet of the first heat exchanger is sequentially communicated with the water cooler and the air cooling tower. A heat transfer medium outlet of the first heat exchanger is communicated with a heat source inlet of the bromine cooler, a heat source outlet of the bromine cooler is communicated with a heat transfer medium inlet of the first heat exchanger to form a circulation, and a cold source outlet and a cold source inlet of the bromine cooler are communicated with the air cooling tower to form a circulation. According to the air separation energy-saving refrigerating system, the bromine refrigerator is used for providing cold energy, the bromine refrigerator is used for preparing the cold energy through heat energy of compressed gas, then effective utilization of waste heat is achieved, valuable energy is provided through energy-saving transformation, meanwhile, heat pollution is reduced, a friendly environment is created, the production and operation cost is reduced, and the air separation energy-saving refrigerating system is suitable for large-scale popularization and application. And the enterprise revenue is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air separation systems, in particular to an air separation energy-saving refrigeration system. Background Art

[0002] The air separation adopts the low-temperature refrigeration process of the French Air Liquide Group, with a designed capacity of 52,000m 3 / h. The main principle is: air: a mixed gas composed of oxygen, nitrogen, inert gas, carbon dioxide, and water vapor. The volume percentage of the main components is 20.93% oxygen, 78.03% nitrogen, and 0.932% argon. The air also contains an indefinite amount of mechanical impurities, hydrocarbons, water vapor, etc. From its composition, it can be seen that air is mainly composed of oxygen, nitrogen and argon, so it can be regarded as an oxygen-nitrogen-argon ternary mixture. This device uses air as raw material to separate oxygen and nitrogen, and adopts a deep freezing internal compression method. The main advantages are: large output, high product purity, low energy consumption, etc. The main process is: first compress the air, cool it, remove harmful impurities, and then liquefy it at low temperature. Using the different boiling points of oxygen, nitrogen, and argon components, the gas and liquid are contacted in the distillation tower to transfer heat and mass to separate them.

[0003] The main processes of the air separation unit are divided into: air filtration and compression system, air precooling system, air purification system, air liquefaction and distillation system, cold production system, and liquid argon distillation system. The main product outputs include: 5.11MPa(a) oxygen, high-pressure nitrogen and ultra-high-pressure nitrogen products (5.3MPa(a), 8.1MPa(a)), 3.71MPa(a) nitrogen, low-pressure nitrogen products (0.42MPa(a), 0.71MPa(a)), liquid oxygen products, liquid nitrogen products, and liquid argon products.

[0004] (1) Compressed air

[0005] The device uses a three-in-one unit to compress the gas. The compressor is divided into four sections. The C01&C50ST air compressor uses MAN Turbine compressor. After on-site investigation, the interstage cooler adopts a built-in type. Considering the importance of the equipment and its actual operability, no interstage modification is performed.

[0006] The compressed air temperature after the four-stage compressor is 95-110°C, the pressure is 4.3MPa, and the flow rate is 4950Nm 3 / min (i.e. 297000Nm 3 / h), the current cooling method is to use the circulating water in the factory to force cooling through the water cooler, which leads to the waste of heat energy.

[0007] (2) Condensation water

[0008] There are 3 condensed water coming out of towers (tower 4 and tower 5) in the factory, with a condensed water back pressure of 0.2MPa, a water temperature of 105℃, a total of 47t / h; it cannot be recovered and a large amount of water vapor is ejected. The condensate to E04212 → condensate tank flow rate is 17t / h; another condensate to E04215 flow rate is 5t / h; V3403 condensed water 10t / h; V3404 condensed water 15t / h, a total of 47t / h, 105℃ condensed water.

[0009] Since the pressure and temperature of condensed water from several places are different, in order to balance the pressure, three recovery tanks are set up in the factory. The condensed water from the three places enters the recovery tanks for flash evaporation into hot water and then is sent to the condensed water total recovery tank. Since the recovery tank is an open design, the flash evaporation of condensed water will not only obtain hot water but also negative pressure steam. This part of the steam will be discharged from the recovery tank, resulting in waste of heat energy and the existence of a "white fog" problem.

[0010] (3) Cold demand

[0011] When the original air separation compressor is exported for purification, the cooling is done by an ice machine. The cooling capacity of the air separation ice machine X60A is 1739KW, the chilled water inlet temperature is 14.79℃, the outlet temperature is 8.3℃, and the flow rate is 231m 3 / h. The original compressor outlet temperature is calculated as 15℃.

[0012] (4) Circulating water

[0013] The circulating water supply temperature is 26℃ and the return water temperature is 35℃.

[0014] In short, in the existing air production process and synthetic ammonia production process, there are problems such as some low-level thermal energy not being utilized in a timely manner and insufficient application of relevant energy-saving and emission reduction technologies. Utility Model Content

[0015] The purpose of the utility model is to provide an air separation energy-saving refrigeration system to solve the problems existing in the above-mentioned prior art. The utility model provides valuable energy through energy-saving transformation, while reducing thermal pollution, creating a friendly environment, reducing production and operation costs, and improving corporate benefits.

[0016] To achieve the above purpose, the utility model provides the following solutions:

[0017] The utility model provides an air separation energy-saving refrigeration system, comprising: an air compression system, a first heat exchanger, a water cooler, a bromide refrigerator and an air cooling tower, wherein the air outlet of the air compression system is connected to the heat source inlet of the first heat exchanger, the heat source outlet of the first heat exchanger is connected to the water cooler and the air cooling tower in sequence, the heat transfer medium outlet of the first heat exchanger is connected to the heat source inlet of the bromide refrigerator, the heat source outlet of the bromide refrigerator and the heat transfer medium inlet of the first heat exchanger are connected to form a cycle, and the cold source outlet and inlet of the bromide refrigerator are both connected to the air cooling tower to form a cycle.

[0018] Preferably, an ice machine is also included, wherein the air compression system, the water cooler, the air cooling tower and the ice machine are existing equipment, and the first heat exchanger and the bromine refrigerator are newly added equipment; the air compression system and the water cooler are connected and controlled by an on-off valve, and the passage between the air compression system and the first heat exchanger is controlled by an on-off valve.

[0019] Preferably, it also includes a condensation recovery system and a second heat exchanger, the condensation recovery system is the original equipment, the second heat exchanger is the new equipment, the condensation recovery system has an open total recovery tank, the second heat exchanger is arranged at the open end of the total recovery tank, and the heat transfer medium passage outlet of the second heat exchanger is connected to the heat source inlet of the bromine refrigerator.

[0020] Preferably, the total recovery tank can also be connected to the heat source inlet of the bromide refrigerator.

[0021] Preferably, the heat source outlet of the bromide refrigerator is connected to the second heat exchanger to form a cycle.

[0022] Preferably, the bromide refrigerator can also be connected to an interstage cooler and provide a cold source for the interstage cooler.

[0023] Compared with the prior art, the utility model has achieved the following technical effects:

[0024] The air separation energy-saving refrigeration system provided by the utility model utilizes a bromide refrigerator to provide cold energy. The bromide refrigerator utilizes the thermal energy of compressed gas to produce cold energy, thereby realizing the effective utilization of waste heat. The application provides valuable energy through energy-saving transformation, while reducing thermal pollution, creating a friendly environment, reducing production and operation costs, and improving corporate benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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 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.

[0026] Figure 1 A structural block diagram of an air separation energy-saving refrigeration system having a first heat exchanger and a second heat exchanger is provided for an embodiment of the utility model;

[0027] Figure 2 This is the structural diagram of the original air separation system in the plant;

[0028] Figure 3 The structural block diagram of the air separation energy-saving refrigeration system after adding the first heat exchanger and the bromide refrigeration machine;

[0029] In the figure: 1-air compression system; 2-first heat exchanger; 3-water cooler; 4-second heat exchanger; 5-total recovery tank; 6-condensate recovery pump; 7-bromine refrigerator; 8-recovery tank; 9-low-temperature hot water storage tank; 10-hot water pump; 11-cold water pump; 12-air cooling tower; 13-ice machine. DETAILED DESCRIPTION

[0030] 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.

[0031] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0032] In view of the problems described in the background technology, the utility model adopts the interstage heat energy of the air compression system (hereinafter referred to as the air compressor) and the system heat energy for refrigeration for the first time to replace the original air separation refrigeration unit method. The following embodiments are used for further explanation.

[0033] Reference Figure 1 to Figure 3As shown, an embodiment of the utility model provides an air separation energy-saving refrigeration system, comprising: an air compression system 1, a first heat exchanger 2, a water cooler 3, a bromide refrigerator 7 and an air cooling tower 12, the air outlet of the air compression system 1 is connected to the heat source inlet of the first heat exchanger 2, the heat source outlet of the first heat exchanger 2 is connected to the water cooler 3 and the air cooling tower 12 in sequence, the heat transfer medium outlet of the first heat exchanger 2 is connected to the heat source inlet of the bromide refrigerator 7, the heat source outlet of the bromide refrigerator 7 and the heat transfer medium inlet of the first heat exchanger 2 are connected to form a cycle, and the cold source outlet and inlet of the bromide refrigerator 7 are both connected to the air cooling tower 12 to form a cycle.

[0034] The low-temperature hot water in the first heat exchanger 2 exchanges heat with the high-temperature gas generated by the air compression system 1 to recover the high-temperature heat of the compressed air. At the same time, the low-temperature hot water is heated to high-temperature hot water and input into the bromide refrigeration machine 7 to perform work.

[0035] The air separation energy-saving refrigeration system provided by the utility model utilizes a bromide refrigerator 7 to provide cold energy, and the bromide refrigerator 7 utilizes the thermal energy of compressed gas to produce cold energy, thereby realizing the effective utilization of waste heat. The present application provides valuable energy through energy-saving transformation, while reducing thermal pollution, creating a friendly environment, reducing production and operation costs, and improving corporate benefits.

[0036] Taking the cost into consideration, large equipment in the factory, such as the air compression system 1, the water cooler 3 and the air cooling tower 12, is not easy to replace. Based on this, the utility model provides the following preferred solution to solve the above problem. The preferred embodiment of the utility model also includes an ice machine 13. The air compression system 1, the water cooler 3, the air cooling tower 12 and the ice machine 13 are original equipment, and the first heat exchanger 2 and the bromine cooler 7 are newly added equipment; the air compression system 1 and the water cooler 3 are connected and controlled by the on-off valve, and the passage between the air compression system 1 and the first heat exchanger 2 is controlled by the on-off valve.

[0037] This embodiment is an improvement on the original air separation system, so as to achieve the purpose of energy saving, reducing thermal pollution, creating a friendly environment, reducing production and operation costs, and improving enterprise benefits.

[0038] During use, when a newly added device fails and cannot operate, the on-off valve is used to disconnect the connection between it and the original device, so that the entire system can still operate in the original manner. Therefore, this embodiment also improves the ability of the entire system to resist risks.

[0039] Specifically, when the device is operating normally:

[0040] Gas circuit: air compression system 1→first heat exchanger 2→water cooler 3→air cooling tower 12;

[0041] Heat source: air compression system 1 → first heat exchanger 2 → bromide refrigeration machine 7;

[0042] Cold source: bromide refrigeration machine 7 → air cooling tower 12.

[0043] When a device fails and needs to use the original system to work:

[0044] Gas circuit: air compression system 1 → water cooler 3 → air cooling tower 12;

[0045] Cold source: ice machine 13 → air cooling tower 12.

[0046] It can be seen that when the equipment provided in the present application operates normally, the heat source utilization is added, that is, the purpose of utilizing the waste heat of the system is achieved.

[0047] In some embodiments, the utility model also includes a condensation recovery system and a second heat exchanger 4. The condensation recovery system is an existing device, and the second heat exchanger 4 is a newly added device. The condensation recovery system has an open total recovery tank 5. The second heat exchanger 4 is set at the open end of the total recovery tank 5. The heat transfer medium passage outlet of the second heat exchanger 4 is connected to the heat source inlet of the bromide refrigerator 7; wherein the heat source outlet of the bromide refrigerator 7 is connected to the second heat exchanger 4 to form a cycle. The high-temperature hot water exchanged by the bromide refrigerator 7 becomes low-temperature hot water. This part of the low-temperature hot water needs to be returned to the newly added first heat exchanger 2 and the second heat exchanger 4 for heat exchange to complete the cycle.

[0048] The original condensation recovery system generally has multiple recovery tanks 8 and a total recovery tank 5. The multiple recovery tanks 8 are connected to the total recovery tank 5. If the original recovery tank 8 in the factory is not in a closed state, the recovery tank 8 will be closed, for example, covered, and a safety valve will be set to ensure safety. The condensed water in the multiple recovery tanks 8 is sent to the total recovery tank 5 through pipelines respectively. The total recovery tank 5 is designed for normal pressure. Multiple condensed waters with different temperatures and pressures will flash into hot water in the total recovery tank 5. At the same time, the flash steam is discharged from the top. A second heat exchanger 4 is set at the flash steam outlet position, and low-temperature hot water is used to condense the flash steam to recover heat and eliminate the "white fog" phenomenon.

[0049] The recovery tank 8 is used to recover hot water from other systems or process steps in the plant. The utility model makes full use of the waste heat in the plant to achieve energy saving.

[0050] In this embodiment, the steam condensate that can be recovered and has a large amount of water vapor ejected plays a role in deoxidizing while recovering heat.

[0051] In some embodiments, the total recovery tank 5 can also be connected to the heat source inlet of the bromide refrigeration machine 7.

[0052] Compared with the above-mentioned embodiment, in this preferred embodiment, the heat source in the hot water in the total recovery tank 5 is more fully utilized.

[0053] More preferably, the high-temperature hot water recovered from the compressed air by the first heat exchanger 2, the high-temperature hot water recovered from the flash steam condensation by the second heat exchanger 4, and the high-temperature hot water in the total recovery tank 5 can be synthesized into one channel of hot water, and the mixed hot water enters the bromine refrigerator 7 to produce cold energy to replace the ice machine 13.

[0054] In some embodiments, the bromide refrigeration machine 7 can also be connected to the interstage cooler and provide a cold source for the interstage cooler. Specifically, the bromide refrigeration machine 7 cools the 28°C interstage cooler circulating water to 23-25°C.

[0055] In some embodiments, a cooling channel for cooling its own components is also provided in the bromide refrigerator 7. The large circulating water in the plant flows to the cooling channel to cool the bromide refrigerator 7 itself. After cooling, the large circulating water in the plant flows out of the bromide refrigerator 7 and forms a cycle.

[0056] In some embodiments, when the air compression system 1 has a plurality of air compressors, a first heat exchanger 2 is added at the last compressed air outlet.

[0057] In some embodiments, reference Figure 1 A low-temperature hot water storage tank 9, a condensate recovery pump 6, a hot water pump 10 and a cold water pump 11 are also provided.

[0058] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An air separation energy-saving refrigeration system, characterized in that: include: An air compression system, a first heat exchanger, a water cooler, a bromide refrigerator and an air cooling tower, wherein the air outlet of the air compression system is connected to the heat source inlet of the first heat exchanger, the heat source outlet of the first heat exchanger is connected to the water cooler and the air cooling tower in sequence, the heat transfer medium outlet of the first heat exchanger is connected to the heat source inlet of the bromide refrigerator, the heat source outlet of the bromide refrigerator and the heat transfer medium inlet of the first heat exchanger are connected to form a cycle, and the cold source outlet and inlet of the bromide refrigerator are both connected to the air cooling tower to form a cycle.

2. The air separation energy-saving refrigeration system according to claim 1 is characterized in that: It also includes an ice machine, the air compression system, the water cooler, the air cooling tower and the ice machine are original equipment in the factory, and the first heat exchanger and the bromide refrigerator are newly added equipment; the air compression system and the water cooler are connected and controlled by an on-off valve, and the passage between the air compression system and the first heat exchanger is controlled by an on-off valve.

3. The air separation energy-saving refrigeration system according to claim 1 is characterized in that: It also includes a condensation recovery system and a second heat exchanger, wherein the condensation recovery system is an existing device and the second heat exchanger is a newly added device. The condensation recovery system has an open total recovery tank, and the second heat exchanger is arranged at the open end of the total recovery tank. The heat transfer medium passage outlet of the second heat exchanger is connected to the heat source inlet of the bromine refrigerator.

4. The air separation energy-saving refrigeration system according to claim 3 is characterized in that: The total recovery tank can also be communicated with the heat source inlet of the bromide refrigerator.

5. The air separation energy-saving refrigeration system according to claim 3 is characterized in that: The heat source outlet of the bromide refrigerator is connected to the second heat exchanger to form a cycle.

6. The air separation energy-saving refrigeration system according to claim 1 is characterized in that: The bromide refrigeration machine can also be connected to the interstage cooler and provide a cold source for the interstage cooler.

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