CN218972412U - Gas buffer system and air separation device - Google Patents

Abstract

The utility model provides a gas buffer system and an air separation device. The gas buffer system comprises a buffer tank, wherein the buffer tank is provided with an air outlet nozzle and is used for supplementing gas to the gas pipeline. The gas buffering system further comprises a temperature acquisition unit, a heater and a controller. The temperature acquisition unit acquires the temperature of the air tap. The heater is arranged to heat the air outlet nozzle. The controller receives the temperature signal acquired by the temperature acquisition unit and sends a switching signal to the heater according to the temperature signal. By adopting the gas buffer system and the air separation device, the buffer system can be effectively prevented from being cold and fragile, and the cost is lower.

Description

Gas buffer system and air separation device

Technical Field

The utility model belongs to the field of industrial gas application, relates to a gas buffer system and also relates to a space division device.

Background

The gas buffer system is widely used in the chemical industry and is commonly used for supplementing chemical process gas. Buffer systems typically include a buffer tank, typically storing high pressure gas. The surge tank typically has an air outlet nozzle. When the pressure of the pipe network is reduced, the buffer tank can timely supply air to the corresponding air pipelines in the pipe network through the air outlet nozzle so as to compensate the pressure drop of the process air. The gas supply process can result in a temperature drop of up to tens or even hundreds of degrees, compared to the initial ambient temperature of the gas buffer system. This is likely to lead to a cold embrittlement of the cushioning system, causing serious accidents, considering the adiabatic effect of the depressurization process. This situation is more common in some cold areas where the ambient temperature is lower.

To prevent the risk of cold embrittlement of the system, relatively low buffer tank design temperatures are currently employed. To accommodate the lower design temperatures, the surge tank needs to be made of a suitable material, which increases costs.

Accordingly, there is a need to provide a gas buffer system that can effectively prevent cold shortness, which can reduce costs compared to solutions employing lower design temperatures.

Disclosure of Invention

The utility model aims to provide a gas buffer system which can effectively prevent the buffer system from being friable.

Another object of the utility model is a gas buffering system that is relatively low cost.

The utility model provides a gas buffer system, which comprises a buffer tank, wherein the buffer tank is provided with an air outlet nozzle and is used for supplementing gas to a gas pipeline. The gas buffering system further comprises a temperature acquisition unit, a heater and a controller. The temperature acquisition unit acquires the temperature of the air tap. The heater is arranged to heat the air outlet nozzle. The controller receives the temperature signal acquired by the temperature acquisition unit and sends a switching signal to the heater according to the temperature signal.

In one embodiment, the gas buffering system further comprises a buffering line, a throttle valve and a pressure acquiring element. The buffer tank supplements gas to the gas pipeline through the buffer pipeline. The throttle valve is arranged on the buffer pipeline. The pressure acquisition element is used for acquiring the pressure of the gas pipeline, and the controller receives the pressure signal acquired by the pressure acquisition element and controls the opening degree of the throttle valve according to the pressure signal.

In one embodiment, the gas buffer system further comprises a flow rate acquisition element for acquiring the flow rate of the gas line, and the controller further receives the flow rate signal acquired by the flow rate acquisition element and controls the opening degree of the throttle valve according to the flow rate signal.

In one embodiment, the controller is configured to set the opening of the throttle valve to a smaller opening of a first opening and a second opening, wherein the first opening and the second opening are openings determined from the flow rate signal and the pressure signal, respectively.

In one embodiment, the controller is configured to turn on the heater when the temperature at the outlet nozzle acquired by the temperature acquisition unit is below a first temperature, and turn off the heater when the temperature at the outlet nozzle acquired is above a second temperature; and/or closing the throttle valve when the acquired temperature at the air outlet nozzle is below a third temperature, wherein the first temperature is lower than the second temperature and higher than the third temperature.

In one embodiment, the heater is an electric tracing band that surrounds the outlet nozzle.

In one embodiment, the temperature acquisition unit comprises a temperature measurement probe sensitive to temperature, the temperature measurement probe is closely attached to the outer wall surface of the air outlet nozzle, and the electric tracing band surrounds the temperature measurement probe.

In one embodiment, the gas buffer system further comprises a heat conducting layer, a part of the heat conducting layer is circumferentially arranged on the outer wall surface of the gas outlet nozzle, the other part of the heat conducting layer is circumferentially arranged outside the temperature measuring probe, and the electric tracing band is circumferentially arranged outside the heat conducting layer.

In one embodiment, the temperature probe is closely attached to the outer wall surface of the portion of the outlet nozzle where the inner diameter is smallest.

The utility model also provides an air separation device which comprises the gas buffer system.

In the gas buffer system, the temperature acquisition unit and the heater are arranged, and the heater is controlled according to the temperature signal acquired by the temperature acquisition unit, so that the gas buffer system can be heated when the temperature is reduced to a certain degree, and the buffer system can be effectively prevented from being friable. Further, in the above gas buffer system, the temperature at the gas outlet nozzle is obtained, and the gas outlet nozzle is heated, which is set according to the position analysis in which cold embrittlement is likely to occur in practice, so that the buffer system can be more effectively prevented from cold embrittlement.

The buffer tank in the above-described gas buffer system can be made of a cheaper material than the case where a more expensive material is required for the buffer tank when a lower design temperature is used, and thus lower costs can be achieved. Moreover, other components of the overall buffer system, such as further described buffer lines, throttle valves, etc., can be made of cheaper materials, thus further reducing costs.

Drawings

The advantages and spirit of the present utility model will be further understood from the following detailed description and the accompanying drawings.

FIG. 1 is an overall schematic of an exemplary gas buffering system.

Fig. 2 is a partial enlarged view of the vicinity of the air outlet nozzle of the surge tank.

Fig. 3 is a schematic diagram exemplarily illustrating a specific heating arrangement.

Detailed Description

Specific embodiments of the present utility model are described in detail below with reference to the accompanying drawings. However, the present utility model should be understood not to be limited to such an embodiment described below, and the technical idea of the present utility model may be implemented in combination with other known technologies or functions, or other technologies identical to those known technologies.

The terms "first" and "second" are used for descriptive purposes only and are not intended to be limiting with respect to time sequence, number, or importance, and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of features indicated, but merely to distinguish one feature from another feature in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly specified otherwise. Likewise, the appearances of the phrase "a" or "an" in this document are not meant to be limiting, but rather describing features that have not been apparent from the foregoing. Likewise, unless a particular quantity of a noun is to be construed as encompassing both the singular and the plural, both the singular and the plural may be included in this disclosure. Likewise, modifiers similar to "about" and "approximately" appearing before a number in this document generally include the number, and their specific meaning should be understood in conjunction with the context.

It should be understood that in the present utility model, "at least one (secondary)" means one (secondary) or a plurality of (secondary). "and/or" is used to describe association relationships of associated objects, meaning that there may be three relationships, e.g., "a and/or B" may mean: only a, only B and both a and B are present, wherein a, B may be singular or plural.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

Fig. 1 schematically illustrates a gas buffering system 10 according to the present utility model. The gas buffer system 10 comprises a buffer tank 1. The buffer vessel 1 has an outlet nozzle 12 for replenishing the gas line 20 with gas. Fig. 2 exemplarily shows a partially enlarged configuration in the vicinity of outlet nozzle 12. The gas buffering system 10 may be used in an air separation plant 100. At this time, the air separation apparatus 100 may include the gas buffer system 10.

Referring to fig. 1 and 2, the gas buffer system 10 further includes a temperature acquisition unit 3, a heater 4, and a controller 5. The temperature acquisition unit 3 acquires the temperature at the tap 12, for example, a temperature sensor. The heater 4 is arranged to heat the outlet nozzle 12, for example a heating coil. The controller 5 receives the temperature signal acquired by the temperature acquisition unit 3, and sends a switching signal to the heater 4 according to the temperature signal. That is, the controller 5 is connected to both the temperature acquisition unit 3 and the heater 4, and controls the switching of the heater 4 based on the temperature signal acquired by the temperature acquisition unit 3.

The controller 5 may be, for example, one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital signal processing devices (DAPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or a combination thereof.

See fig. 2, the outlet nozzle 12, i.e. the nozzle protruding from the tank wall 11 in the buffer tank 1 for outlet air.

In the gas buffer system 10, the controller 5 controls the on/off of the heater 4 according to the temperature signal acquired by the temperature acquisition unit 3, so that the gas buffer system 10 can be heated when the temperature is reduced to a certain degree, and thus the gas buffer system 10 can be effectively prevented from being cold and fragile.

Experiments have shown that the most likely site for icing of the gas cushion system 10 when depressurized for a short period of time, e.g., seconds to minutes, is the gas outlet nozzle 12. The temperature acquisition unit 3 acquires the temperature of the part, the heater 4 heats the part, and the initial temperature is raised, so that the buffer tank 1 and the whole gas buffer system 10 can be effectively prevented from being cold and crisp when entering a gas supply state.

Since heating can be automatically achieved, a higher design temperature can be used when designing the buffer tank 1, and thus the buffer tank 1 and the buffer pipe 6, the throttle valve 7, etc. described later can be made of materials which are weak in low temperature resistance and thus cheaper. Thus, the overall cost is lower.

Referring to fig. 1, the gas buffering system 10 may further include a buffering line 6. The buffer vessel 1 can supplement the gas line 20 with gas via the buffer line 6. That is, the air outlet 12 of the buffer tank 1 communicates with one end (upper end in fig. 1) of the buffer tube 6, and the other end (lower end in fig. 1) of the buffer tube 6 merges into the air tube 20. Thereby, the buffer vessel 1 and the gas vessel 20 are communicated by the buffer vessel 6, so that the buffer vessel 1 can replenish the gas vessel 20 with gas.

The gas buffering system 10 may further comprise a throttle valve 7. A throttle valve 7 may be provided in the buffer line 6. That is, the opening and closing of the throttle valve 7 can realize the flow and blocking of the flow in the buffer pipe 6, and the opening degree of the throttle valve 7 can determine the flow rate of the flow in the buffer pipe 6, that is, the gas flow rate of the gas supplied from the buffer tank 1 to the gas pipe 20. Maximum opening means that the throttle valve 7 is in a fully open state, and zero opening means that the throttle valve 7 is in a fully closed state.

The gas buffering system 10 may further comprise a pressure acquisition element 8, e.g. a pressure sensor, for acquiring the pressure of the gas line 20. The controller 5 may receive the pressure signal acquired by the pressure acquisition element 8 and control the opening degree of the throttle valve 7 according to the pressure signal. That is, the controller 5 may send a control signal for controlling the opening degree of the throttle valve 7 to the throttle valve 7 (specifically, a positioner of the throttle valve 7) based on the pressure signal acquired by the pressure acquiring element 8.

For example, when the controller 5 determines that the pressure of the gas line 20 detected by the pressure sensor is reduced, the throttle valve 7 may be opened in time to compensate for the pressure drop. Further, the higher the degree of pressure decrease (i.e., the smaller the actually detected pressure), the larger the opening degree of the throttle valve 7 may be made. As mentioned previously, this throttling process sometimes results in a temperature drop of up to a hundred degrees. When the temperature drops to a certain extent, the controller 5 may turn on the heater 4 to heat the outlet nozzle 12. When, for example, it is determined that the pressure gradually recovers, the opening degree of the throttle valve 7 may be gradually reduced until zero (i.e., closed), thereby ending the buffer gas supply. This allows for an automatic control of the whole buffer gas supply and the heating cold-embrittlement prevention.

Experiments have also shown that when a buffer line 6 and a throttle valve 7 are provided, the lines around the throttle valve 7 are also very prone to icing. The heater 4 heats the air outlet nozzle 12, and the temperature of the upstream of the buffer pipeline 6 can effectively avoid cold shortness when the whole gas buffer system 10 enters a throttling state.

Referring to fig. 1, the gas buffering system 10 may further include a flow obtaining element 9, such as a flow meter, for obtaining the flow of the gas line 20. The controller 5 may also receive the flow rate signal acquired by the flow rate acquisition element 9 and control the opening degree of the throttle valve 7 according to the flow rate signal. That is, the controller 5 may also send a control signal for controlling the opening degree of the throttle valve 7 to the throttle valve 7 based on the flow rate signal acquired by the flow rate acquisition element 9.

For example, when the flow rate acquired by the flow rate acquisition element 9 exceeds a target flow rate, for example, 50000Nm3/h, the controller 5 may signal the throttle valve 7 to decrease the opening degree. More specifically, the controller 5 may determine the opening degree of the throttle valve 7 corresponding thereto from the flow rate acquired by the flow rate acquisition element 9. By providing the flow rate obtaining element 9, the opening degree of the throttle valve 7 is controlled according to the flow rate signal to perform flow rate control, the buffer throttle time can be optimized.

Referring to fig. 1, the controller 5 may be configured to set the opening degree of the throttle valve 7 to a smaller opening degree of the first opening degree P1 and the second opening degree P2. The first opening P1 and the second opening P2 are openings determined based on the flow rate signal and the pressure signal, respectively. That is, the first opening P1 is an opening originally determined by the controller 5 from the flow rate signal acquired by the flow rate acquisition element 9, and the second opening P2 is an opening originally determined by the controller 5 from the pressure signal acquired by the pressure acquisition element 8. Finally, the controller 5 compares the first opening P1 and the second opening P2, selects the smaller one (for example, P1 is equal to or smaller than P2, and P1) of them, and controls the opening of the throttle valve 7 to the smaller one.

The controller 5 may be configured to turn on the heater 4 when the temperature at the outlet nozzle 12 acquired by the temperature acquisition unit 3 is below the first temperature T1, and to turn off the heater 4 when the temperature at the outlet nozzle 12 acquired is above the second temperature T2. The controller 5 may also be configured to close the throttle valve 7 when the temperature at the outlet nozzle 12 is acquired below the third temperature T3. Wherein the first temperature T1 is lower than the second temperature T2 and higher than the third temperature T3.

When the temperature of the air outlet nozzle 12 is detected to be lower than the third temperature T3, the throttle valve 7 is closed timely, so that safety protection can be performed. For example, the temperature at outlet nozzle 12 may be raised to 20-60 ℃ and maintained within this temperature range. The specific temperature control situation can be determined according to the calculation conditions of the different buffer tanks 1. This can effectively solve the consequences of the temperature drop effect caused by throttling. For example, the temperatures T1, T2, T3 may be 35℃and 45℃and-60℃respectively. When the temperature at the outlet mouth 12 is detected below, for example, 35 c, the heater 4 is turned on in time, which can avoid the temperature being so low as to cause cold shortness in advance. When the temperature at the outlet nozzle 12 is detected to be above 45 deg.c, for example, the heater 4 is turned off in time, not only saving energy, but also avoiding heating the temperature too high to negatively affect the gas line 20.

It will be appreciated that the controller 5 may be a single controller or may be a plurality of separate or even independent controllers. For example, the controller 5 may be divided into a controller that controls the temperature and a controller that controls the throttle opening, which may be independent of each other without interfering with each other. The connection of the controller 5 to the elements such as the temperature acquiring element 3, the heater 4, the throttle valve 7, the pressure acquiring element 8, the flow acquiring element 9, etc. may be a wired connection or a wireless connection.

Fig. 3 illustrates the arrangement positions of the temperature acquisition unit 3, the heater 4, and the like in the vicinity of the outlet nozzle 12 in more detail than fig. 2. As previously described in connection with fig. 2 and 3, heater 4 may be an electrical heat trace strip that is wrapped around outlet nozzle 12. An electric tracing band is a device for maintaining or increasing the temperature of a pipe (herein, an outlet nozzle 12) by radiating heat from a heat tracing cable around the pipe, and may generally include conductive polymers, metal wires, insulating sheaths, and the like. The electric tracing band has high flexibility, can adapt to the air outlet nozzles 12 with different sizes, is also beneficial to cladding the air outlet nozzles 12 along the whole length of the air outlet nozzles 12, and has high heating efficiency. It will be appreciated that fig. 2 and 3 are both schematic and do not show a wound-like flexible construction, such as an electric heat tracing band, and that fig. 2 does not show a gap-filling heat conducting layer 2, which will be described later.

As shown in fig. 3, the temperature acquisition unit 3 includes a temperature probe 31 that is sensitive to temperature. For example, the temperature acquisition unit 3 may be a thermocouple, and the temperature probe 31, i.e. the temperature probe of the thermocouple, typically comprises a temperature sensitive material that is sensitive to temperature, is able to detect temperature and is able to give a varying electrical signal as the temperature changes. The temperature measuring probe 31 is closely attached to the outer wall surface 13 of the air outlet nozzle 12. An electric tracing band as the heater 4 is surrounded outside the temperature measuring probe 31. In fig. 3, the gas buffering system 10 further comprises a heat conducting layer 2. A portion 21 of the heat-conducting layer 2 is arranged circumferentially on the outer wall surface 13 of the outlet nozzle 12. Another portion 22 of the thermally conductive layer 2 surrounds the outside of the temperature probe 31. The electric tracing band as the heater 4 is then surrounded outside the heat conductive layer 2. The heat conducting layer 2 is a coating layer made of heat conducting material and wrapped outside the air outlet nozzle 12. An electric heat tracing band as a heater 4 is surrounded outside the heat conductive layer 2. The thermally conductive material may be, for example, aluminum/copper wire, thermally conductive silicone, etc. The heat conduction layer 2 can compensate the clearance between the temperature measurement probe 31 and the electric tracing band, so that the temperature detected by the temperature measurement probe 31 wrapped in the heat conduction layer is more accurate, and the whole temperature control is more accurate.

Referring to fig. 2, the temperature probe 31 may be closely attached to the outer wall surface 13 of the portion 121 of the outlet nozzle 12 where the inner diameter is smallest. Thus, the temperature probe 31 measures the weakest point of the nozzle 12.

As a comparative example, an instrument gas manifold of an air separation plant was taken as an example of a gas line. In this comparative example, a buffer tank is arranged, and a buffer line and a throttle valve are also provided, but a temperature acquisition unit, a heater, and the like are not provided. For example, during normal standby, the pressure of the meter gas manifold is about 50barg and the ambient temperature is about-13 ℃. When the pressure in the meter gas manifold is detected to drop to, for example, 8barg, the throttle valve is opened to compensate for the pressure differential from 50barg to 8 barg. The duration is about 30 min. The temperature of the air outlet nozzle of the buffer tank is reduced to about 100 ℃ through calculation. Even when low temperature, low stress conditions are considered, the design temperature of the buffer tank is still below-19 ℃. Therefore, plain carbon steel cannot be used as a material for the surge tank.

By providing the temperature acquisition unit 3, the heater 4, and the like, the above-described gas buffer system 10 can raise the standby temperature to, for example, 40 ℃. The design temperature of the buffer tank 1 can be set to be above-19 ℃, and plain carbon steel can be used as a material.

Each aspect or embodiment defined herein may be combined with any other aspect or embodiment unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

The preferred embodiments of the present utility model have been described in the specification, and the above embodiments are merely for illustrating the technical solution of the present utility model and not for limiting the present utility model. All technical solutions that can be obtained by logic analysis, reasoning or limited experiments according to the inventive concept by those skilled in the art shall be within the scope of the present utility model.

Claims (10)

1. A gas buffering system comprising a buffer tank having an outlet nozzle for replenishing a gas to a gas line, the gas buffering system further comprising:

a temperature acquisition unit for acquiring the temperature of the air outlet nozzle;

a heater arranged to heat the outlet nozzle; and

and a controller which receives the temperature signal acquired by the temperature acquisition unit and sends a switching signal to the heater according to the temperature signal.

2. The gas buffering system of claim 1, further comprising:

the buffer tank supplements gas to the gas pipeline through the buffer pipeline;

the throttle valve is arranged on the buffer pipeline; and

and the controller is used for receiving the pressure signal acquired by the pressure acquisition element and controlling the opening degree of the throttle valve according to the pressure signal.

3. The gas buffering system of claim 2, further comprising a flow rate acquisition element for acquiring a flow rate of the gas line, the controller further receiving a flow rate signal acquired by the flow rate acquisition element and controlling an opening degree of the throttle valve in accordance with the flow rate signal.

4. A gas buffering system according to claim 3, wherein the controller is configured to set the opening of the throttle valve to a smaller opening of a first opening and a second opening, wherein the first opening and the second opening are openings determined from the flow rate signal and the pressure signal, respectively.

5. The gas buffering system of claim 2, wherein the controller is configured to,

turning on the heater when the temperature at the outlet nozzle acquired by the temperature acquisition unit is below a first temperature, and turning off the heater when the acquired temperature at the outlet nozzle is above a second temperature; and/or

And closing the throttle valve when the acquired temperature at the air outlet nozzle is lower than a third temperature, wherein the first temperature is lower than the second temperature and higher than the third temperature.

6. The gas buffering system of claim 1, wherein the heater is an electric tracing band surrounding the outlet nozzle.

7. The gas buffering system of claim 6, wherein the temperature acquisition unit comprises a temperature probe sensitive to temperature, the temperature probe is closely attached to the outer wall surface of the gas outlet nozzle, and the electric tracing band surrounds the temperature probe.

8. The gas buffering system of claim 7, further comprising a thermally conductive layer, a portion of the thermally conductive layer being circumferentially disposed on an outer wall surface of the gas outlet nozzle, another portion of the thermally conductive layer being circumferentially disposed outside the temperature probe, and the electrical trace thermal band being circumferentially disposed outside the thermally conductive layer.

9. The gas buffer system of claim 8, wherein the temperature probe is in close proximity to an outer wall surface of a portion of the outlet nozzle having a minimum inner diameter.

10. An air separation plant comprising a gas buffer system as claimed in any one of claims 1 to 9.

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