Electric heater for purification system of air separation device

Abstract

The utility model provides an air separation unit purification system electric heater which comprises a first electric heater and a second electric heater, and 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 on an outlet pipe section, behind the corresponding electric heater and in front of the outlet cut-off butterfly valve, on the corresponding branch pipeline, 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 working condition alarm module is connected with the dry-burning data acquisition module and is used for acquiring the 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] This utility model relates to the field of automated control technology for air separation units, and in particular to an electric heater for an air separation unit purification system. Background Technology

[0002] The activation process of molecular sieves in an air separation unit consists of four stages: heating, cold blowing, pressurization, and depressurization. Generally, two molecular sieves are used alternately. In the heating stage, an electric heater heats the waste nitrogen, which is then passed into the molecular sieve to regenerate the adsorbent. The heating element in the electric heater primarily removes heat through heat exchange with the flowing waste nitrogen; therefore, the heater's operating status is crucial for the normal operation of the air separation unit. Existing air separation units typically have temperature detection points at the outlet pipe section of the electric heater, along with interlocking heating elements for power adjustment to prevent excessive heating power from damaging the equipment. However, in actual production, if the heating pipe valves malfunction or operators fail to properly open and close relevant valves when switching electric heaters, the flow of waste nitrogen in the electric heater may be obstructed, resulting in dry burning. In this case, the heater outlet temperature detection point is located in a dead gas zone, and the high temperature from dry burning cannot be promptly transmitted to the sensor. Even if the electric heater itself has a temperature sensor, uneven heating and stagnant gas flow within the heater may prevent the sensor from detecting these abnormalities in time, leading to dry burning of the electric heater. This can damage the heating element or, in severe cases, cause a fire. Utility Model Content

[0003] An embodiment of this utility model provides an electric heater for a purification system of an air separation unit, which improves the timeliness and accuracy of the dry-burning warning of the electric heater in the air separation unit, and effectively prevents the equipment from being damaged or causing safety accidents due to dry burning.

[0004] To achieve the above objectives, on the one hand, an electric heater for a purification system of an air separation unit is provided. The electric heater for the purification system of the air separation unit includes a first electric heater and a second electric heater, which are connected in parallel. The characteristic of the first electric heater and the second electric heater is that the branch pipeline of each electric heater includes: an inlet shut-off butterfly valve, an outlet shut-off butterfly valve, an outlet temperature measuring point, a dry burning data acquisition module, and a dry burning alarm module.

[0005] The inlet shut-off butterfly valve is installed at the inlet of the corresponding electric heater on the corresponding branch pipeline and is used to control the flow of polluted nitrogen gas into the corresponding electric heater.

[0006] The outlet shut-off butterfly valve is installed at the outlet of the corresponding electric heater on the corresponding branch pipeline and is used to control the on / off of the polluted nitrogen gas entering the corresponding electric heater.

[0007] The outlet temperature measuring point is set on the outlet pipe section of the corresponding branch pipeline after the corresponding electric heater and before the outlet shut-off butterfly valve, and is used to monitor the temperature of the polluted nitrogen gas flowing out from the corresponding electric heater.

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

[0009] The inlet pressure sensor is located on the corresponding branch pipeline after the inlet shut-off butterfly valve and before the corresponding electric heater; the outlet pressure sensor is located on the corresponding branch pipeline after the corresponding electric heater and before the outlet shut-off butterfly valve.

[0010] The dry-burning alarm module is connected to the dry-burning data acquisition module and is used to acquire 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 pressure difference between the inlet and outlet is less than a preset value.

[0011] Preferably, the air separation unit purification system electric heater further includes: a regional control system and an emergency shutdown control system, wherein the regional control system acquires the outlet temperature of each of the first and second electric heaters 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 area control system and triggers an emergency shutdown procedure when a predetermined temperature anomaly is detected.

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

[0014] Preferably, the air separation unit purification system electric heater, wherein the dry-burning alarm module is activated when either the first electric heater or the second electric heater is in operation; and / or,

[0015] The dry-burning alarm module is used to issue an alarm when either the first electric heater or the second electric heater is in operation, and the inlet shut-off butterfly valve and outlet shut-off butterfly valve corresponding to the first electric heater and the second electric heater are not normally opened.

[0016] The above technical solution has the following technical effects:

[0017] This invention achieves precise control and safety monitoring of the heating process by installing inlet and outlet shut-off butterfly valves, outlet temperature measuring points, dry-burning data acquisition modules, and dry-burning alarm modules on the branch pipelines of each of the first and second electric heaters. This design not only effectively controls the on / off state of the nitrogen gas entering and leaving the electric heater, ensuring operational flexibility and safety, but also monitors the outlet temperature of the electric heater in real time to prevent overheating damage. Furthermore, through real-time acquisition and analysis of inlet and outlet pressure data, the device can detect the risk of dry burning early and issue timely alarms, thereby avoiding heater damage or safety accidents caused by no medium flow. This significantly improves the safety and reliability of the electric heater operation and provides convenient operation and maintenance methods for maintenance personnel, ensuring the overall stable operation of the air separation unit. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the electric heater of the purification system of an air separation unit according to an embodiment of the present invention;

[0019] The meanings of the reference numerals in the attached figures are as follows:

[0020] EH101 First electric heater, V101 First electric heater inlet shut-off butterfly valve, V102 First electric heater outlet shut-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 alarm module;

[0021] EH201 second electric heater, V201 second electric heater inlet shut-off butterfly valve, V202 second electric heater outlet shut-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 alarm module;

[0022] UZ101 area control system, ESC101 emergency stop control system. Detailed Implementation

[0023] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and 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 drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0024] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0025] Example 1:

[0026] During normal production, the air separation unit operates with one electric heater in operation and one on standby. When switching heaters, if the operator activates the first electric heater EH101 / second electric heater EH201 but fails to simultaneously open the corresponding inlet shut-off butterfly valves V101 / V201 and outlet shut-off butterfly valves V102 / V202, the nitrogen pollution inside the corresponding electric heater will not flow. Consequently, the outlet temperature measuring points TICA101 / TICA201 will be located in a dead zone, and the high temperature cannot be detected and alerted in time through these measuring points. This can lead to the corresponding electric heater burning out and potentially damaging the equipment. In this text, " / " indicates "or".

[0027] Therefore, in order to improve the timeliness and accuracy of the dry-burning warning of the electric heater in the air separation unit and effectively prevent the equipment from being damaged or causing safety accidents due to dry burning, the embodiments of this utility model provide an electric heater for the air separation unit. Figure 1 This is a schematic diagram of the electric heater in the purification system of an air separation unit according to an embodiment of this utility model. Figure 1 As shown, the air separation unit purification system electric heater includes a first electric heater EH101 and a second electric heater EH201, which are connected in parallel. Each of the first and second electric heaters has a branch line including: an inlet shut-off butterfly valve such as inlet shut-off butterfly valve V101 / V201, an outlet shut-off butterfly valve such as outlet shut-off butterfly valve V102 / V202, an outlet temperature measuring point such as outlet temperature measuring point TICA101 / TICA201, a dry burning data acquisition module such as dry burning data acquisition module 1-1 / 2-1, and a dry burning alarm module such as dry burning alarm module UA101 / UA201.

[0028] Among them, the inlet shut-off butterfly valve V101 / V201 is installed at the inlet of the corresponding electric heater EH101 / EH201 on the corresponding branch pipeline to control the on / off of the polluted nitrogen gas entering the corresponding electric heater EH101 / EH201.

[0029] The outlet shut-off butterfly valve V102 / V202 is installed at the outlet of the corresponding electric heater EH101 / EH201 on the corresponding branch pipeline to control the on / off of the polluted nitrogen gas entering the corresponding electric heater EH101 / EH201.

[0030] The outlet temperature measuring points TICA101 / TICA201 are set on the outlet pipe section after the corresponding electric heater EH101 / EH201 and before the outlet shut-off butterfly valve on the corresponding branch pipeline, and are used to monitor the temperature of the polluted nitrogen gas flowing out from the corresponding electric heater EH101 / EH201.

[0031] The dry-burning data acquisition module 1-1 / 2-1 is used to monitor the pressure data at 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: inlet pressure sensor PT101 / PT201 and outlet pressure sensor PT102 / PT202.

[0032] The inlet pressure sensor is installed on the corresponding branch pipeline after the inlet shut-off butterfly valve and before the corresponding electric heater EH101 / EH201; the outlet pressure sensor is installed on the corresponding branch pipeline after the corresponding electric heater EH101 / EH201 and before the outlet shut-off butterfly valve.

[0033] The dry-burning alarm module UA101 / UA201 is connected to the dry-burning data acquisition module. It is used to acquire the pressure data of the electric heater inlet and outlet collected by the dry-burning data acquisition module, and to issue an alarm when the pressure difference between the inlet and outlet is less than a preset value.

[0034] Preferably, the electric heater dry burning early warning module 1-2 / 2-2 includes: dry burning condition alarm module UA101 / UA201.

[0035] Preferably, the air separation unit purification system electric heater further includes: a zone control system UZ101 and an emergency shutdown control system ESC101. Specifically, the zone control system obtains the outlet temperature of each of the first electric heater EH101 and the second electric heater EH201 through an 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 zone control system UZ101 and triggers an emergency shutdown procedure when a predetermined temperature anomaly is detected.

[0036] Preferably, the air separation unit in the air separation purification system is an air separation unit that uses an electric heater to heat waste nitrogen for molecular sieve regeneration. Specifically, the air separation unit includes: air separation oxygen production or air separation nitrogen production.

[0037] Preferably, the dry-burning alarm module is activated when either the first electric heater EH101 or the second electric heater EH201 is in operation.

[0038] Preferably, the dry-burning alarm module is used to issue an alarm when either the first electric heater EH101 or the second electric heater EH201 is in operation and the inlet shut-off butterfly valve and outlet shut-off butterfly valve corresponding to the first electric heater EH101 and the second electric heater EH201 are not normally opened.

[0039] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. An electric heater for a purification system of an air separation unit, the electric heater 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, Each of the first and second electric heaters has a branch pipeline including: an inlet shut-off butterfly valve, an outlet shut-off butterfly valve, an outlet temperature measuring point, a dry-burning data acquisition module, and a dry-burning alarm module. The inlet shut-off butterfly valve is installed at the inlet of the corresponding electric heater on the corresponding branch pipeline and is used to control the flow of polluted nitrogen gas into the corresponding electric heater. The outlet shut-off butterfly valve is installed at the outlet of the corresponding electric heater on the corresponding branch pipeline and is used to control the on / off of the polluted nitrogen gas entering the corresponding electric heater. The outlet temperature measuring point is set on the outlet pipe section of the corresponding branch pipeline after the corresponding electric heater and before the outlet shut-off butterfly valve, and is used to monitor the temperature of the polluted nitrogen gas flowing out from the corresponding electric heater. The dry-burning data acquisition module is used to monitor the pressure data at the inlet and outlet of the corresponding electric heater in real time. The dry-burning data acquisition module includes an inlet pressure sensor and an outlet pressure sensor. The inlet pressure sensor is located on the corresponding branch pipeline after the inlet shut-off butterfly valve and before the corresponding electric heater; the outlet pressure sensor is located on the corresponding branch pipeline after the corresponding electric heater and before the outlet shut-off butterfly valve. The dry-burning alarm module is connected to the dry-burning data acquisition module and is used to acquire 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 pressure difference between the inlet and outlet is less than a preset value.

2. The electric heater of the air separation unit purification system according to claim 1, characterized in that, Also includes: A zone control system and an emergency stop control system, wherein the zone control system acquires the outlet temperature of each of the first and second electric heaters through the outlet temperature measuring point, and transmits the outlet temperature to the emergency stop control system. The emergency shutdown control system receives data transmitted by the area control system and triggers an emergency shutdown procedure when a predetermined temperature anomaly is detected.

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

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

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