Air separation low-temperature waste liquid cooling capacity recovery device

Abstract

The utility model discloses an air separation low-temperature waste liquid cooling capacity recovery device which comprises a low-temperature waste liquid collecting tank and a built-in heat exchanger coil pipe, the built-in heat exchanger coil pipe is arranged in the low-temperature waste liquid collecting tank, and a first connecting pipe communicated with one end of the built-in heat exchanger coil pipe is arranged at the top of the low-temperature waste liquid collecting tank. A second connecting pipe communicated with the other end of the built-in heat exchanger coil pipe is arranged at the bottom end of the low-temperature waste liquid collecting tank, one end of the first connecting pipe is communicated with an inlet pipe, one end of the second connecting pipe is communicated with an outlet pipe, and one side of the low-temperature waste liquid collecting tank is communicated with a low-temperature waste liquid inlet pipe and a low-temperature waste liquid overflow pipe; and the other side of the low-temperature waste liquid collecting tank is communicated with a low-temperature waste gas discharge pipe. The air separation low-temperature waste liquid cooling capacity recovery device is simple in equipment, low in investment and beneficial to implementation of carbon neutralization and carbon emission reduction in an air separation device.

Description

Technical Field

[0001] The utility model relates to the technical field of deep cold separation, in particular to a device for recovering cold amount of low-temperature waste liquid from air separation. Background Art

[0002] An air separation unit is a set of industrial equipment used to separate the various gas components in the air and produce oxygen, nitrogen, argon and other gases as air components. When the air separation unit is started, stopped or operated normally, it will temporarily discharge cryogenic liquids, such as liquid oxygen, liquid nitrogen, liquid argon or a mixture of two or three of the above substances. The conventional treatment methods for gasification of low-temperature waste liquid in air separation units mainly include steam heating and direct discharge to the atmosphere and air heating and direct discharge to the atmosphere. Steam heating and direct discharge to the atmosphere means that when the low-temperature waste liquid vaporizer of the air separation unit uses steam heating, the low-temperature waste liquid is evenly distributed on the upper part of the steam spray pipe mouth, and the low-temperature liquid is vaporized by high-temperature steam and then directly discharged into the atmosphere; air heating and direct discharge to the atmosphere means that when the low-temperature waste liquid vaporizer of the air separation unit uses air heating, a fan is used to introduce normal temperature air into the low-temperature waste liquid collection tank, and the low-temperature liquid is vaporized and directly discharged into the atmosphere.

[0003] The above two methods of treating low-temperature waste liquid from air separation require a lot of energy, steam heating consumes heat energy or air consumes electricity. Although the treatment is simple and easy, as the future trend of carbon neutrality and carbon emission reduction becomes more and more obvious, the above two treatment methods will cause additional carbon emissions and are not very economical.

[0004] Based on the above factors, it is necessary to design an air separation low-temperature waste liquid cooling capacity recovery device. Utility Model Content

[0005] In order to solve the above-mentioned defects, the utility model provides an air separation low-temperature waste liquid refrigeration recovery device. The air separation low-temperature waste liquid refrigeration recovery device has simple equipment, low investment and is helpful to implement carbon neutrality and carbon emission reduction in the air separation device.

[0006] In order to achieve the above-mentioned purpose, the technical solution provided by the utility model is a low-temperature waste liquid cooling capacity recovery device for air separation, comprising a low-temperature waste liquid collecting tank and a built-in heat exchanger coil, wherein the built-in heat exchanger coil is arranged inside the low-temperature waste liquid collecting tank, a first connecting pipe connected to one end of the built-in heat exchanger coil is arranged at the top of the low-temperature waste liquid collecting tank, a second connecting pipe connected to the other end of the built-in heat exchanger coil is arranged at the bottom of the low-temperature waste liquid collecting tank, one end of the first connecting pipe is connected to an inlet pipe, one end of the second connecting pipe is connected to an outlet pipe, one side of the low-temperature waste liquid collecting tank is connected to a low-temperature waste liquid inlet pipe and a low-temperature waste liquid overflow pipe, the other side of the low-temperature waste liquid collecting tank is connected to a low-temperature waste gas discharge pipe, the top of the low-temperature waste liquid collecting tank is connected to an exhaust gas discharge pipe, a first valve is arranged on the surface of the inlet pipe, a second valve is arranged on the surface of the low-temperature waste liquid inlet pipe, and a third valve is arranged on the surface of the low-temperature waste gas discharge pipe.

[0007] Preferably, the cryogenic waste liquid inlet pipe and the cryogenic waste gas discharge pipe are arranged near the bottom of the cryogenic waste liquid collection tank, and the cryogenic waste liquid overflow pipe is arranged near the top of the cryogenic waste liquid collection tank.

[0008] Preferably, the gas introduced into the inlet pipe is one or more of nitrogen, oxygen or argon.

[0009] Preferably, the first valve and the second valve are normally closed solenoid valves, a support frame is provided at the bottom of the low-temperature waste liquid collection tank, a PLC controller is provided in the support frame, and the first valve and the second valve are electrically connected to the control end of the PLC controller.

[0010] Preferably, a temperature sensor and a liquid level sensor are provided in the low-temperature waste liquid collection tank, and the output ends of the temperature sensor and the liquid level sensor are electrically connected to the input end of the PLC controller.

[0011] Preferably, the highest liquid level detected by the liquid level sensor is above the coil of the built-in heat exchanger, and the low-temperature waste liquid overflow pipe is located above the highest liquid level detected by the liquid level sensor.

[0012] Preferably, a gas inlet control valve is provided at one end of the inlet pipe, a low-temperature waste liquid inlet control valve is provided at one end of the low-temperature waste liquid inlet pipe, and a storage tank inlet control valve is provided at one end of the outlet pipe.

[0013] The utility model adopts the above-mentioned technical scheme, and the beneficial effects include: this type of air separation low-temperature waste liquid cold recovery device, by arranging the built-in heat exchanger coil inside the low-temperature waste liquid collection tank, the waste liquid immerses the built-in heat exchanger coil, thereby ensuring that impurities in the low-temperature waste liquid do not precipitate, and at the same time cooperates with the low-temperature waste gas discharge pipe to discharge regularly to reduce impurity accumulation; in addition, the built-in heat exchanger coil also saves the floor space of the device, and the device has a simple structure and low investment; the latent heat of the low-temperature waste liquid can be almost completely recovered, and liquid nitrogen or other low-temperature liquids with a similar flow rate can be produced as by-products. The cold utilization is more full and reasonable, and no additional steam or air used for gasification is consumed. The by-product low-temperature liquid can also generate additional economic benefits, which is in line with the current policy requirements of carbon neutrality and carbon emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0015] Figure 2 This is a schematic diagram of the internal structure of the low-temperature waste liquid collection tank of the utility model.

[0016] In the figure: 1-low-temperature waste liquid collection tank, 2-built-in heat exchanger coil, 3-first connecting pipe, 4-second connecting pipe, 5-inlet pipe, 6-outlet pipe, 7-low-temperature waste liquid inlet pipe, 8-waste gas discharge pipe, 9-low-temperature waste gas discharge pipe, 10-low-temperature waste liquid overflow pipe, 11-first valve, 12-second valve, 13-third valve, 14-support frame, 15-PLC controller, 16-gas inlet control valve, 17-low-temperature waste liquid inlet control valve, 18-temperature sensor, 19-liquid level sensor, 20-tank inlet control valve. DETAILED DESCRIPTION

[0017] The utility model is further described below in conjunction with the accompanying drawings.

[0018] Example 1: Please refer to Figure 1-2 The utility model provides a technical solution: a device for recovering cold energy of low-temperature waste liquid of air separation, comprising a low-temperature waste liquid collecting tank 1 and a built-in heat exchanger coil 2, the built-in heat exchanger coil 2 is arranged inside the low-temperature waste liquid collecting tank 1 and is fixedly connected to the low-temperature waste liquid collecting tank 1 through a bracket, and the built-in type saves the floor space of the device, a first connecting pipe 3 connected to one end of the built-in heat exchanger coil 2 is arranged on the top of the low-temperature waste liquid collecting tank 1, a second connecting pipe 4 connected to the other end of the built-in heat exchanger coil 2 is arranged on the bottom of the low-temperature waste liquid collecting tank 1, one end of the first connecting pipe 3 is connected to an inlet pipe 5, one end of the second connecting pipe 4 is connected to an outlet pipe 6, the gas introduced into the inlet pipe 5 is one or more of nitrogen, oxygen or argon, and the gas discharged from the outlet pipe 6 is one or more of corresponding liquid nitrogen, liquid oxygen or liquid argon.

[0019] One side of the cryogenic waste liquid collecting tank 1 is connected with a cryogenic waste liquid inlet pipe 7 and a cryogenic waste liquid overflow pipe 10, and the cryogenic waste liquid inlet pipe 7 is connected to the air separation equipment. The other side of the cryogenic waste liquid collecting tank 1 is connected with a cryogenic waste gas discharge pipe 9, and the cryogenic waste liquid inlet pipe 7 and the cryogenic waste gas discharge pipe 9 are arranged near the bottom of the cryogenic waste liquid collecting tank 1, and the cryogenic waste liquid overflow pipe 10 is arranged near the top of the cryogenic waste liquid collecting tank 1. The cryogenic waste liquid overflow pipe 10 extends to a safe place, and a collection cofferdam paved with gravel is arranged at the safe place to ensure safe gasification.

[0020] The top of the low-temperature waste liquid collection tank 1 is connected to an exhaust gas discharge pipe 8, and the low-temperature waste gas after gasification or reheating is directly discharged from the exhaust gas discharge pipe 8 to a safe place in the atmosphere. A first valve 11 is provided on the surface of the inlet pipe 5, and the first valve 11 is used to control the gas entering the built-in heat exchanger coil 2. A second valve 12 is provided on the surface of the low-temperature waste liquid inlet pipe 7, and the second valve 12 is used to control the liquid level of the low-temperature waste liquid collection tank 1. A third valve 13 is provided on the surface of the low-temperature waste gas discharge pipe 9, and part of the liquid is discharged by periodically opening the third valve 13 to prevent impurities from accumulating in the low-temperature waste liquid collection tank 1.

[0021] The first valve 11 and the second valve 12 are normally closed solenoid valves. A support frame 14 is provided at the bottom of the low-temperature waste liquid collection tank 1. A PLC controller 15 is provided in the support frame 14. The first valve 11 and the second valve 12 are electrically connected to the control end of the PLC controller 15. The PLC controller and the solenoid valves are purchased from the market and installed according to their instructions. The valves are controlled by the PLC controller to avoid manual operation.

[0022] A temperature sensor 18 and a liquid level sensor 19 are provided in the low-temperature waste liquid collection tank 1, and the output ends of the temperature sensor 18 and the liquid level sensor 19 are electrically connected to the input end of the PLC controller 15. The PLC controller 15 controls the opening and closing of the first valve 11 according to the signal of the temperature sensor 18, and controls the opening and closing of the second valve 12 according to the signal of the liquid level sensor 19.

[0023] The temperature sensor 18 is used to detect the temperature inside the tank. When the temperature inside the tank rises, the first valve 11 prevents the gas from entering the built-in heat exchanger coil 2. The highest liquid level detected by the liquid level sensor 19 is above the built-in heat exchanger coil 2. The low-temperature waste liquid overflow pipe 10 is located above the highest liquid level detected by the liquid level sensor 19. The liquid level sensor 19 ensures that the main part of the built-in heat exchanger coil 2 can be immersed in the waste liquid to ensure that impurities in the low-temperature waste liquid do not precipitate.

[0024] A gas inlet control valve 16 is provided at one end of the inlet pipe 5 , a low-temperature waste liquid inlet control valve 17 is provided at one end of the low-temperature waste liquid inlet pipe 7 , and a storage tank inlet control valve 20 is provided at one end of the outlet pipe 6 .

[0025] When in use, the gas inlet control valve 16 is connected to the gas source and opened, one end of the low-temperature waste liquid inlet control valve 17 is connected to the air separation equipment, the storage tank inlet control valve 20 is connected to the storage tank, the low-temperature waste liquid inlet control valve 17 and the second valve 12 are opened, and the low-temperature waste liquid enters the low-temperature waste liquid collection tank 1 through the low-temperature waste liquid inlet pipe 7. After the liquid gradually rises and immerses the built-in heat exchanger coil 2, the liquid level sensor 19 outputs a signal, and the PLC controller 15 controls the second valve 12 to close. After the temperature sensor 18 detects that the internal temperature is suitable for liquefaction, the first valve 11 is controlled to open by the PLC controller 15, and nitrogen, oxygen or argon is gradually introduced into the built-in heat exchanger coil 2. After the gas is liquefied, it is sent to the storage tank for storage or use through the outlet pipe 6, and the low-temperature waste gas after reheating can be low temperature or room temperature. The low-temperature waste gas after gasification or reheating is discharged to a safe place in the atmosphere through the waste gas discharge pipe 8.

[0026] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0027] The above description is only a preferred embodiment of the prior art type of fixing and installation of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An air separation low-temperature waste liquid cooling capacity recovery device, characterized in that: The invention comprises a low-temperature waste liquid collection tank (1) and a built-in heat exchanger coil (2), wherein the built-in heat exchanger coil (2) is arranged inside the low-temperature waste liquid collection tank (1), a first connecting pipe (3) connected to one end of the built-in heat exchanger coil (2) is arranged at the top of the low-temperature waste liquid collection tank (1), a second connecting pipe (4) connected to the other end of the built-in heat exchanger coil (2) is arranged at the bottom of the low-temperature waste liquid collection tank (1), one end of the first connecting pipe (3) is connected to an inlet pipe (5), and one end of the second connecting pipe (4) is connected to a The low-temperature waste liquid collection tank (1) has an outlet pipe (6), one side of the low-temperature waste liquid collection tank (1) is connected to a low-temperature waste liquid inlet pipe (7) and a low-temperature waste liquid overflow pipe (10), the other side of the low-temperature waste liquid collection tank (1) is connected to a low-temperature waste gas discharge pipe (9), the top of the low-temperature waste liquid collection tank (1) is connected to a waste gas discharge pipe (8), a first valve (11) is provided on the surface of the inlet pipe (5), a second valve (12) is provided on the surface of the low-temperature waste liquid inlet pipe (7), and a third valve (13) is provided on the surface of the low-temperature waste gas discharge pipe (9).

2. The air separation low-temperature waste liquid cooling capacity recovery device according to claim 1, characterized in that: The low-temperature waste liquid inlet pipe (7) and the low-temperature waste gas discharge pipe (9) are arranged near the bottom of the low-temperature waste liquid collection tank (1), and the low-temperature waste liquid overflow pipe (10) is arranged near the top of the low-temperature waste liquid collection tank (1).

3. The air separation low-temperature waste liquid refrigeration recovery device according to claim 1 is characterized in that: The gas introduced into the inlet pipe (5) is one or more of nitrogen, oxygen or argon.

4. The air separation low-temperature waste liquid cooling capacity recovery device according to claim 1, characterized in that: The first valve (11) and the second valve (12) are normally closed solenoid valves. A support frame (14) is provided at the bottom of the low-temperature waste liquid collection tank (1). A PLC controller (15) is provided in the support frame (14). The first valve (11) and the second valve (12) are electrically connected to the control end of the PLC controller (15).

5. The air separation low-temperature waste liquid refrigeration recovery device according to claim 4 is characterized in that: A temperature sensor (18) and a liquid level sensor (19) are arranged in the low-temperature waste liquid collection tank (1), and the output ends of the temperature sensor (18) and the liquid level sensor (19) are electrically connected to the input end of the PLC controller (15).

6. The air separation low-temperature waste liquid refrigeration recovery device according to claim 5, characterized in that: The highest liquid level detected by the liquid level sensor (19) is above the built-in heat exchanger coil (2), and the low-temperature waste liquid overflow pipe (10) is located above the highest liquid level detected by the liquid level sensor (19).

7. The air separation low-temperature waste liquid cooling capacity recovery device according to claim 1, characterized in that: A gas inlet control valve (16) is provided at one end of the inlet pipe (5), a low-temperature waste liquid inlet control valve (17) is provided at one end of the low-temperature waste liquid inlet pipe (7), and a storage tank inlet control valve (20) is provided at one end of the outlet pipe (6).

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