Air separation unit purification system electric heater and dry burning early warning method thereof

Abstract

The invention provides an air separation unit purification system electric heater and a dry burning early warning method thereof.The air separation unit purification system electric heater comprises a first electric heater body and a second electric heater body; a branch pipeline of each electric heater comprises an inlet cut-off butterfly valve, an outlet cut-off butterfly valve, an outlet temperature measuring point, a dry burning data acquisition module and a dry burning working condition alarm module; wherein the outlet temperature measuring point is arranged at an outlet pipe section behind the corresponding electric heater and in front of the outlet cut-off butterfly valve, and is used for monitoring the temperature of the waste nitrogen gas flowing out of the corresponding electric heater; the dry burning data acquisition module is used for monitoring pressure data of inlets and outlets of corresponding electric heaters in real time; the dry burning condition alarm module is used for obtaining pressure data of the inlet and outlet of the electric heater and giving an alarm when the inlet and outlet pressure difference is smaller than a preset value. By means of the technical scheme, timeliness and accuracy of dry burning early warning of the electric heater are improved, and equipment is effectively prevented from being damaged or causing safety accidents due to dry burning.

Description

Technical Field

[0001] The invention relates to the technical field of automatic control of air separation devices, and in particular to an electric heater of a purification system of an air separation device and a dry burning early warning method thereof. Background Art

[0002] The activation process of molecular sieves in air separation units is divided into four stages, namely heating, cold blowing, boosting, and pressure relief. Generally, two molecular sieves are used in turn. In the heating stage, the electric heater heats the dirty nitrogen, and the heated dirty nitrogen is passed into the molecular sieve to regenerate the adsorbent. The heating tube in the electric heater mainly exchanges heat with the flowing dirty nitrogen to remove heat. Therefore, the working state of the heater is crucial to the normal production of the air separation unit. The electric heater of the existing air separation unit is generally equipped with a temperature detection point in the outlet pipe section, and the interlocking heating tube is adjusted to avoid excessive heating power to damage the equipment; however, in actual production, if the valve of the heating pipeline fails or the operator does not open and close the relevant valves normally when switching the electric heater, the flow of dirty nitrogen in the electric heater is blocked and it is in a dry burning state. At this time, the temperature detection point of the heater outlet is located in the dead gas zone, and the dry burning high temperature cannot be transmitted to the sensor in time. If the electric heater body is equipped with temperature detection, it may also be due to uneven heating in the electric heater and the gas does not flow, causing the temperature sensor to fail to sense the above abnormality in time, thereby causing the electric heater to dry burn, which may damage the heating tube at the least or cause a fire at the worst. Summary of the invention

[0003] The embodiments of the present invention provide an air separation unit purification system electric heater and a dry burning warning method thereof, so as to improve the timeliness and accuracy of the dry burning warning of the air separation unit electric heater, and effectively prevent the equipment from being damaged or causing safety accidents due to dry burning.

[0004] In order to achieve the above-mentioned object, on the one hand, an electric heater for purification system of an air separation device is provided, wherein the electric heater for purification system of the air separation device comprises a first electric heater and a second electric heater, wherein the first electric heater and the second electric heater are connected in parallel, and characterized in that a branch pipeline of each of the first electric heater and the second electric heater comprises: an inlet cut-off butterfly valve, an outlet cut-off butterfly valve, an outlet temperature measuring point, a dry burning data acquisition module and a dry burning condition alarm module;

[0005] Wherein, the inlet cut-off butterfly valve is arranged at the inlet of the corresponding electric heater on the corresponding branch pipeline, and is used to control the on-off of the dirty nitrogen gas entering the corresponding electric heater;

[0006] The outlet cut-off butterfly valve is arranged at the outlet of the corresponding electric heater on the corresponding branch pipeline, and is used to control the on-off of the dirty nitrogen gas entering the corresponding electric heater;

[0007] The outlet temperature measuring point is arranged on the outlet pipe section after the corresponding electric heater and before the outlet cut-off butterfly valve on the corresponding branch pipeline, and is used to monitor the temperature of the contaminated nitrogen gas flowing out of the corresponding electric heater;

[0008] The dry-burning data acquisition module is used to monitor the pressure data of the inlet and outlet of the corresponding electric heater in real time, and the dry-burning data acquisition module includes: an inlet pressure sensor and an outlet pressure sensor;

[0009] Wherein, the inlet pressure sensor is arranged on the corresponding branch pipeline after the inlet cut-off butterfly valve and before the corresponding electric heater; the outlet pressure sensor is arranged on the corresponding branch pipeline after the corresponding electric heater and before the outlet cut-off butterfly valve;

[0010] The dry burning condition alarm module is connected to the dry burning data acquisition module, and is used to obtain the pressure data of the inlet and outlet of the electric heater collected by the dry burning data acquisition module, and to issue an alarm when the inlet and outlet pressure difference of the inlet and outlet pressure data is less than a preset value.

[0011] Preferably, the air separation unit purification system electric heater, wherein, further comprises: a regional control system and an emergency shutdown control system, wherein the regional control system obtains the outlet temperature of each of the first electric heater and the second electric heater through the outlet temperature measuring point, and transmits the outlet temperature to the emergency shutdown control system;

[0012] The emergency shutdown control system receives data transmitted by the regional control system and triggers an emergency shutdown program when a predetermined temperature abnormality is detected.

[0013] Preferably, the air separation unit purification system electric heater, wherein the air separation unit in the air separation unit purification system electric heater is an air separation unit that uses an electric heater to heat contaminated nitrogen for molecular sieve regeneration, and the air separation unit includes: air separation oxygen production or air separation nitrogen production.

[0014] Preferably, in the air separation unit purification system electric heater, the dry burning condition alarm module is enabled when any one of the first electric heater and the second electric heater is in working state; and / or,

[0015] The dry burning condition alarm module is used to issue an alarm when any one of the first electric heater and the second electric heater is in working state and the inlet cut-off butterfly valve and the outlet cut-off butterfly valve corresponding to the first electric heater and the second electric heater are not opened normally.

[0016] On the other hand, an embodiment of the present invention provides a dry burning warning method for an electric heater of a purification system of an air separation unit, wherein the dry burning warning method is applicable to the electric heater of the purification system of an air separation unit described in any one of the above items, and the dry burning warning method comprises:

[0017] S1, acquiring inlet and outlet pressure data of the first electric heater and / or the second electric heater in real time, and calculating the inlet and outlet pressure difference;

[0018] S2, determining whether the inlet and outlet pressure difference is less than a preset value, if so, issuing a dry-boiling alarm instruction; if not, returning to step S1.

[0019] Preferably, in the dry burning warning method for electric heaters in a purification system of an air separation unit, step S1 is performed only when either the first electric heater or the second electric heater is in a working state.

[0020] Preferably, in the dry burning warning method for the electric heater of the purification system of the air separation unit, the preset value in step S2 is pre-set according to a predetermined pressure difference value corresponding to normal production, and the preset value is lower than the predetermined pressure difference value by a predetermined threshold value.

[0021] Preferably, in the dry burning warning method for the electric heater of the purification system of the air separation unit, the value range of the predetermined threshold is 2 to 3 kPa.

[0022] On the other hand, an embodiment of the present invention provides a computer-readable storage medium, wherein the storage medium stores at least one program, and the at least one program is executed by a processor to implement the dry burning warning method for the electric heater of the purification system of an air separation unit as described above.

[0023] On the other hand, an embodiment of the present invention provides a computer program product, including a computer program, wherein when the computer program is executed by a processor, it implements any of the above-mentioned dry burning warning methods for the electric heater of the purification system of the air separation unit.

[0024] The above technical solution has the following technical effects:

[0025] The embodiment of the present invention realizes precise control and safety monitoring of the heating process by arranging inlet and outlet cut-off butterfly valves, outlet temperature measuring points, dry burning data acquisition modules and dry burning working condition alarm modules on the branch pipelines of each electric heater in the first electric heater and the second electric heater. This design can not only effectively control the on-off state of the dirty nitrogen gas entering and leaving the electric heater, ensuring the flexibility and safety of operation; it can also monitor the outlet temperature of the electric heater in real time to prevent overheating and damage to the equipment; and through the real-time collection and analysis of the inlet and outlet pressure data, the device can detect the risk of dry burning at an early stage and issue an alarm in time, thereby avoiding damage to the heater or safety accidents caused by the lack of medium flow, significantly improving the safety and reliability of the operation of the electric heater, and also providing maintenance personnel with convenient operation and maintenance means, ensuring the stable operation of the overall system of the air separation unit;

[0026] Another embodiment of the present invention accurately determines whether the electric heater is in a dry-burning state by real-time monitoring of the pressure data of the inlet and outlet of the electric heater and calculating the pressure difference; when it is detected that the inlet and outlet pressure difference is lower than a preset value, it indicates that there may be no medium flowing inside the heater, resulting in an increased risk of dry-burning, and an alarm command is immediately issued to remind the operator to take measures, which not only improves the timeliness and accuracy of the dry-burning condition identification, avoids the safety hazards caused by delayed or inaccurate temperature detection, but also effectively prevents equipment damage and potential safety accidents caused by dry-burning. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of an electric heater of an air separation unit purification system according to an embodiment of the present invention;

[0028] The meanings of the reference numerals are as follows:

[0029] EH101 first electric heater, V101 first electric heater inlet cut-off butterfly valve, V102 first electric heater outlet cut-off butterfly valve, TICA101 first electric heater outlet temperature measuring point, PT101 first electric heater inlet pressure sensor, PT102 first electric heater outlet pressure sensor, 1-1 first electric heater dry burning data acquisition module, 1-2 first electric heater dry burning early warning module, UA101 first electric heater dry burning working condition alarm module;

[0030] EH201 second electric heater, V201 second electric heater inlet cut-off butterfly valve, V202 second electric heater outlet cut-off butterfly valve, TICA201 second electric heater outlet temperature measuring point, PT201 second electric heater inlet pressure sensor, PT202 second electric heater outlet pressure sensor, 2-1 first electric heater dry burning data acquisition module, 2-2 first electric heater dry burning early warning module, UA201 second electric heater dry burning working condition alarm module;

[0031] UZ101 zone control system, ESC101 emergency shutdown control system. DETAILED DESCRIPTION

[0032] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0033] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0034] Embodiment 1:

[0035] In normal production, the air separation unit has one electric heater in use and one in reserve. When switching the heaters, if the operator activates the first electric heater EH101 / the second electric heater EH201 but does not open the corresponding electric heater's inlet cut-off butterfly valve V101 / V201 and outlet cut-off butterfly valve V102 / V202 at the same time, the corresponding electric heater does not flow dirty nitrogen, and the outlet temperature measuring point TICA101 / TICA201 is located in the dead air zone. The high temperature cannot be detected and warned in time through the outlet temperature measuring point TICA101 / TICA201, resulting in dry burning of the corresponding electric heater and damage to the equipment. In this article, " / " means "or".

[0036] Therefore, in order to improve the timeliness and accuracy of the dry burning warning of the air separation unit electric heater and effectively prevent the equipment from being damaged or causing safety accidents due to dry burning, an embodiment of the present invention provides an air separation unit electric heater. Figure 1 FIG. 1 is a schematic diagram of the structure of an electric heater of an air separation unit purification system according to an embodiment of the present invention. Figure 1 As shown, the electric heater of the purification system of the air separation unit includes a first electric heater EH101 and a second electric heater EH201, the first electric heater EH101 and the second electric heater EH201 are connected in parallel, and the branch pipeline of each of the first electric heater and the second electric heater includes: an inlet cut-off butterfly valve such as an inlet cut-off butterfly valve V101 / V201, an outlet cut-off butterfly valve such as an outlet cut-off butterfly valve V102 / V202, an outlet temperature measuring point such as an outlet temperature measuring point TICA101 / TICA201, a dry burning data acquisition module such as a dry burning data acquisition module 1-1 / 2-1 and a dry burning condition alarm module such as a dry burning condition alarm module UA101 / UA201;

[0037] Among them, the inlet cut-off butterfly valve V101 / V201 is arranged at the inlet of the corresponding electric heater EH101 / EH201 on the corresponding branch pipeline, and is used to control the on-off of the dirty nitrogen gas entering the corresponding electric heater EH101 / EH201;

[0038] The outlet cut-off butterfly valve V102 / V202 is arranged at the outlet of the corresponding electric heater EH101 / EH201 on the corresponding branch pipeline, and is used to control the on-off of the dirty nitrogen gas entering the corresponding electric heater EH101 / EH201;

[0039] The outlet temperature measuring point TICA101 / TICA201 is set on the outlet pipe section after the corresponding electric heater EH101 / EH201 and before the outlet cut-off butterfly valve on the corresponding branch pipeline, and is used to monitor the temperature of the contaminated nitrogen gas flowing out of the corresponding electric heater EH101 / EH201;

[0040] The dry-burning data acquisition module 1-1 / 2-1 is used to monitor the pressure data of the inlet and outlet of the corresponding electric heater EH101 / EH201 in real time. The dry-burning data acquisition module 1-1 / 2-1 includes: an inlet pressure sensor PT101 / PT201 and an outlet pressure sensor PT102 / PT202;

[0041] Among them, the inlet pressure sensor is arranged on the corresponding branch pipeline after the inlet cut-off butterfly valve and before the corresponding electric heater EH101 / EH201; the outlet pressure sensor is arranged on the corresponding branch pipeline after the corresponding electric heater EH101 / EH201 and before the outlet cut-off butterfly valve;

[0042] The dry burning condition alarm module UA101 / UA201 is connected to the dry burning data acquisition module, and is used to obtain the pressure data of the inlet and outlet of the electric heater collected by the dry burning data acquisition module, and to issue an alarm when the inlet and outlet pressure difference of the inlet and outlet pressure data is less than a preset value.

[0043] Preferably, the electric heater dry-burning warning module 1-2 / 2-2 includes: a dry-burning condition alarm module UA101 / UA201.

[0044] Preferably, the electric heater of the purification system of the air separation unit also includes: a regional control system UZ101 and an emergency shutdown control system ESC101. Specifically, the regional control system obtains the outlet temperature of each electric heater in the first electric heater EH101 and the second electric heater EH201 through the outlet temperature measuring point, and transmits the outlet temperature to the emergency shutdown control system ESC101; the emergency shutdown control system ESC101 receives the data transmitted by the regional control system UZ101, and triggers the emergency shutdown procedure when a predetermined temperature abnormality is detected.

[0045] Preferably, the air separation unit in the electric heater of the air separation unit purification system is an air separation unit that uses an electric heater to heat contaminated nitrogen for molecular sieve regeneration. Specifically, the air separation unit includes: air separation oxygen production or air separation nitrogen production.

[0046] Preferably, the dry burning condition alarm module is activated when any one of the first electric heater EH101 and the second electric heater EH201 is in working state;

[0047] Preferably, the dry burning condition alarm module is used to issue an alarm when any one of the first electric heater EH101 and the second electric heater EH201 is in working state and the inlet cut-off butterfly valve and the outlet cut-off butterfly valve corresponding to the first electric heater EH101 and the second electric heater EH201 are not opened normally.

[0048] Embodiment 2:

[0049] An embodiment of the present invention further provides a dry burning early warning method for an electric heater of a purification system of an air separation device, which is applicable to the electric heater of the purification system of the air separation device in the above embodiment. The dry burning early warning method comprises:

[0050] S1, acquiring the inlet and outlet pressure data of the first electric heater EH101 and / or the second electric heater EH201 in real time, and calculating the inlet and outlet pressure difference;

[0051] S2, determining whether the inlet and outlet pressure difference is less than a preset value, if so, issuing a dry-boiling alarm instruction; if not, returning to step S1.

[0052] Preferably, step S1 is performed only when either the first electric heater EH101 or the second electric heater EH201 is in operation.

[0053] Preferably, the preset value in step S2 is pre-set according to a predetermined pressure difference value corresponding to normal production, and the preset value is lower than the predetermined pressure difference value by a predetermined threshold value.

[0054] Preferably, the predetermined threshold value ranges from 2 to 3 kPa.

[0055] Embodiment three:

[0056] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method in the embodiment of the present invention are implemented.

[0057] If the module / unit integrated in the computer unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory) and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction.

[0058] Embodiment 4:

[0059] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the steps of the method described above are implemented.

[0060] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. An electric heater for a purification system of an air separation device, comprising a first electric heater and a second electric heater, wherein the first electric heater and the second electric heater are connected in parallel, characterized in that: The branch pipeline of each of the first electric heater and the second electric heater comprises: an inlet cut-off butterfly valve, an outlet cut-off butterfly valve, an outlet temperature measuring point, a dry burning data acquisition module and a dry burning condition alarm module; Wherein, the inlet cut-off butterfly valve is arranged at the inlet of the corresponding electric heater on the corresponding branch pipeline, and is used to control the on-off of the dirty nitrogen gas entering the corresponding electric heater; The outlet cut-off butterfly valve is arranged at the outlet of the corresponding electric heater on the corresponding branch pipeline, and is used to control the on-off of the dirty nitrogen gas entering the corresponding electric heater; The outlet temperature measuring point is arranged on the outlet pipe section after the corresponding electric heater and before the outlet cut-off butterfly valve on the corresponding branch pipeline, and is used to monitor the temperature of the contaminated nitrogen gas flowing out of the corresponding electric heater; The dry-burning data acquisition module is used to monitor the pressure data of the inlet and outlet of the corresponding electric heater in real time, and the dry-burning data acquisition module includes: an inlet pressure sensor and an outlet pressure sensor; Wherein, the inlet pressure sensor is arranged on the corresponding branch pipeline after the inlet cut-off butterfly valve and before the corresponding electric heater; the outlet pressure sensor is arranged on the corresponding branch pipeline after the corresponding electric heater and before the outlet cut-off butterfly valve; The dry burning condition alarm module is connected to the dry burning data acquisition module, and is used to obtain the pressure data of the inlet and outlet of the electric heater collected by the dry burning data acquisition module, and to issue an alarm when the inlet and outlet pressure difference of the inlet and outlet pressure data is less than a preset value.

2. The electric heater for purification system of air separation unit according to claim 1, characterized in that: Also includes: A regional control system and an emergency shutdown control system, wherein the regional control system obtains the outlet temperature of each of the first electric heater and the second electric heater through the outlet temperature measuring point, and transmits the outlet temperature to the emergency shutdown control system; The emergency shutdown control system receives data transmitted by the regional control system and triggers an emergency shutdown program when a predetermined temperature abnormality is detected.

3. The electric heater for purification system of air separation unit according to claim 1, characterized in that: The air separation device of the air separation device purification system is an air separation device that uses an electric heater to heat contaminated nitrogen for molecular sieve regeneration, and the air separation device includes: air separation oxygen production or air separation nitrogen production.

4. The electric heater for purification system of air separation unit according to claim 1, characterized in that: The dry burning condition alarm module is activated when any one of the first electric heater and the second electric heater is in working state; and / or, The dry burning condition alarm module is used to issue an alarm when any one of the first electric heater and the second electric heater is in working state and the inlet cut-off butterfly valve and the outlet cut-off butterfly valve corresponding to the first electric heater and the second electric heater are not opened normally.

5. A dry burning warning method for an electric heater in a purification system of an air separation unit, characterized in that: Applicable to the electric heater of the purification system of the air separation unit according to any one of claims 1 to 4 above, the dry burning warning method comprises: S1, acquiring inlet and outlet pressure data of the first electric heater and / or the second electric heater in real time, and calculating the inlet and outlet pressure difference; S2, determining whether the inlet and outlet pressure difference is less than a preset value, if so, issuing a dry-boiling alarm instruction; if not, returning to step S1.

6. The dry burning warning method of the electric heater of the air separation unit purification system according to claim 5 is characterized in that: Step S1 is performed only when either the first electric heater or the second electric heater is in the working state.

7. The dry burning warning method of the electric heater of the air separation unit purification system according to claim 5 is characterized in that: The preset value in step S2 is pre-set according to a predetermined pressure difference value corresponding to normal production, and the preset value is lower than the predetermined pressure difference value by a predetermined threshold value.

8. The dry burning warning method of the electric heater of the air separation unit purification system according to claim 7 is characterized in that: The predetermined threshold value ranges from 2 to 3 kPa.

9. A computer-readable storage medium, characterized in that: At least one program is stored in the storage medium, and the at least one program is executed by the processor to implement the dry burning warning method for the electric heater of the purification system of the air separation unit as described in any one of claims 5 to 8.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the dry burning warning method for the electric heater of the purification system of an air separation unit as described in any one of claims 5 to 8 is implemented.

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