Thermocouple positioning method for lean and dense phase temperature difference of catalytic cracking regenerator

Abstract

A dilute phase regenerator and a dense phase regenerator are respectively provided with a thermocouple, a boundary line of a third quadrant and a fourth quadrant is taken as a datum line, a positive 30-degree angle and a negative 30-degree angle are taken as the datum line, and a middle point between two adjacent cyclone separators is taken as the datum line; height positioning: a dense-phase thermocouple is arranged at the lower 1 / 3 position of the total height of the dense-phase regenerator; the dilute-phase thermocouple is positioned to be flush with the lower edge of an inlet of the cyclone separator; horizontal positioning is carried out at a middle point between two adjacent cyclone separators; and height positioning: the dilute phase regenerator is higher than the original dilute phase thermocouple area. The device has the following advantages that the structural design is reasonable, the temperature is relatively stable, the interference is small, the dense-phase temperature change can be truly reflected, and the dense-phase temperature change can be reflected in the first time.

Description

Technical Field

[0001] The present invention relates to the technical field of thermocouple positioning, specifically to a method for positioning thermocouples for the temperature difference between the dilute phase and the dense phase in a catalytic cracking regenerator. Background Technique

[0002] For existing thermocouples, the dense phase temperature is affected in the reverse and counteracting directions by the low temperature (400 degrees) from the reactor, causing the temperature difference between the dilute phase and the dense phase to be distorted. For operators, it is difficult to judge and operate, prone to misjudgment, prone to operation fluctuations, and prone to carbon accumulation and secondary combustion.

[0003] In the regenerator of the catalytic cracking unit, the biggest original design mistake is that the dense phase thermocouple in the dilute phase and dense phase is designed at the worst position, resulting in fluctuations (unstable operation) during normal production. In severe cases, carbon accumulation and secondary combustion occur, leading to unstable production of the entire catalytic cracking unit. This is a mistake in the original design. Since the introduction of the first catalytic unit in China more than sixty years ago, the thermocouples in the dilute phase and dense phase have never been modified.

[0004] Comparison of the installation height of the dense phase thermocouple: The original design has a small temperature difference between the dilute phase and the dense phase, poor judgment accuracy, and cannot correctly and timely judge the change of the dense phase temperature. The newly designed one is easy to operate, not prone to misjudgment, not prone to operation fluctuations, not prone to carbon accumulation and secondary combustion. The displayed temperature difference between the dilute phase and the dense phase is large, easy to accurately judge, can truly reflect the dense phase temperature, and can reflect the change of the dense phase temperature in the first time (the change of the dense phase temperature is from bottom to top). Summary of the Invention

[0005] The purpose of the present invention is to solve the problems in the background technique and provide a method for positioning thermocouples for the temperature difference between the dilute phase and the dense phase in a catalytic cracking regenerator.

[0006] To solve the above technical problems, the technical solution provided by the present invention is: For the method of positioning thermocouples for the temperature difference between the dilute phase and the dense phase in a catalytic cracking regenerator, each of the dilute phase regenerator and the dense phase regenerator is provided with a thermocouple. Taking the intersection line of the third quadrant and the fourth quadrant as the reference line, plus or minus 30 degrees, and the midpoint between two adjacent cyclone separators; Height positioning: For the dense phase thermocouple, at the lower 1 / 3 of the total height of the dense phase regenerator; Dilute phase thermocouple positioning: At the same level as the lower edge of the cyclone separator inlet; Horizontal positioning: At the midpoint between two adjacent cyclone separators; Height positioning: In the area of the dilute phase regenerator higher than the original dilute phase thermocouple, and the dense phase regenerator lower than the original dense phase thermocouple.

[0007] As a preferred solution, a simplified version of the temperature difference between the dilute phase and the dense phase: Without adding new thermocouples for the temperature difference between the dilute phase and the dense phase, changing the dense phase thermocouple of the original temperature difference between the dilute phase and the dense phase to the dense phase thermocouple in the third quadrant, and keeping the position of the dilute phase thermocouple of the original dilute phase and dense phase unchanged.

[0008] As a preferred solution, changing all the thermocouples for the temperature difference between the dilute phase and the dense phase to the third quadrant.

[0009] As a preferred solution, the differential temperature between the dilute phase and the dense phase is designed such that a same-image dilute-phase thermometer is above the dense-phase thermometer.

[0010] As a preferred solution, the differential temperature between the dilute phase and the dense phase is designed for different images, and the dilute-phase thermometer is designed obliquely above or directly above the dense-phase thermometer.

[0011] The present invention has the following advantages: reasonable structural design, relatively stable temperature, small interference, can truly reflect the temperature change of the dense phase, can truly reflect the temperature change of the dense phase, and can reflect the temperature change of the dense phase in the first time. Specific embodiments

[0012] In the description of the embodiments of the present invention, if a certain feature is referred to as "set", "fixed", "connected", "installed" on another feature, it can be directly set, fixed, connected, or installed on another feature, or indirectly set, fixed, connected, or installed on another feature. In the description of the embodiments of the present invention, if "several" is involved, its meaning is more than one; if "multiple" is involved, its meaning is more than two; if "greater than", "less than", "exceeding" are involved, they should all be understood as not including the present number; if "above", "below", "within" are involved, they should all be understood as including the present number. If "first" and "second" are involved, they should be understood as used to distinguish technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0013] Embodiment

[0014] A method for positioning thermocouples of the differential temperature between the dilute phase and the dense phase of a catalytic cracking regenerator: Each of the dilute-phase regenerator and the dense-phase regenerator is provided with a thermocouple. Taking the intersection line of the third quadrant and the fourth quadrant as the reference line, within plus or minus 30 degrees, at the midpoint between two adjacent cyclone separators; height positioning: for the dense-phase thermocouple, at the lower 1 / 3 of the total height of the dense-phase regenerator; dilute-phase thermocouple positioning: at the same level as the lower edge of the cyclone separator inlet; horizontal positioning: at the midpoint between two adjacent cyclone separators; height positioning: in the area of the dilute-phase regenerator higher than the original dilute-phase thermocouple and in the area of the dense-phase regenerator lower than the original dense-phase thermocouple.

[0015] As a preferred implementation of this embodiment, a simplified version of the differential temperature between the dilute phase and the dense phase: No new dilute-phase and dense-phase thermocouples are added. The dense-phase thermocouple of the original differential temperature between the dilute phase and the dense phase is changed to the dense-phase thermocouple in the third quadrant, and the position of the dilute-phase thermocouple of the original dilute phase and dense phase remains unchanged.

[0016] As a preferred implementation of this embodiment, all the thermocouples of the differential temperature between the dilute phase and the dense phase are changed to the third quadrant, using the original dilute-phase and dense-phase temperature thermocouples in the third quadrant, and its effect is much better than the original design of the differential temperature between the dilute phase and the dense phase.

[0017] As a preferred implementation of this embodiment, the dense-phase and dilute-phase temperature difference is designed such that the same dilute-phase thermometer is above the dense-phase thermometer.

[0018] As a preferred implementation of this embodiment, the dense-phase and dilute-phase temperature difference is designed to be different. The dilute-phase thermometer is designed to be obliquely above or directly above the dense-phase thermometer.

[0019] The working principle of the present invention: In the regenerator's vortex fluidized bed, most of the catalysts pass through this area, where the temperature is relatively stable, the interference is small, it can truly reflect the temperature change in the dense phase, and can reflect the temperature change in the dense phase in the first time.

[0020] The reaction temperature is automatically controlled by the slide valve. Therefore, the slide valve is usually in the process of opening or closing. When the slide valve opens, the regenerated catalyst entering the regenerator will increase, and the amount of coke will also increase, causing the dense-phase concentration in the regenerator to rise and the dense-phase and dilute-phase temperature difference to become smaller. However, since the amount of low-temperature catalyst entering the dense phase of the regenerator also increases, the dense-phase temperature is reduced; when the slide valve closes, the dense-phase temperature will decrease, but the amount of low-temperature catalyst entering the regenerator will also decrease, increasing the dense-phase temperature. Therefore, it is in an opposite and counteracting relationship with the dense-phase and dilute-phase.

[0021] During normal operation, most of the time it is stable because the opening and closing range of the slide valve is small, and the dense-phase temperature difference is much larger than the counteracting amount. When the opening and closing range of the slide valve increases, the counteracting amount will also increase, even exceeding the dense-phase change amount, resulting in carbon accumulation, the dense-phase temperature rising to 850 - 950 degrees, then to secondary combustion, the dense-phase temperature decreasing, the dilute-phase temperature rising to 850 - 950 degrees, pushing the slide valve to fully open and close, causing carbon accumulation, secondary combustion, and carbon accumulation, repeating in a cycle.

[0022] The positioning of the dilute-phase thermocouple is based on the lower edge of the inlet of the cyclone separator. It is above the dense-phase thermocouple in the dense-phase and dilute-phase, between the two cyclone separators.

[0023] Both of the two dense-phase and dilute-phase thermocouples are in the fourth quadrant.

[0024] Positioning of the dense-phase and dilute-phase temperature difference thermocouple:

[0025] Positioning of the dense-phase thermocouple:

[0026] Positioning of the dense-phase thermoelectric: At 1 / 3 of the total height of the dense phase of the high regenerator, at an angle of 0 - 30 degrees.

[0027] Positioning of the dilute-phase thermocouple: At the same level as the lower edge of the inlet of the cyclone separator. At an angle of 0 - 40 degrees, at the midpoint between the two cyclone separators.

[0028] The regenerator's vortex fluidized bed. Most of the catalysts pass through this area. The temperature is relatively stable with little interference, and it can truly reflect the temperature change in the dense phase, truly reflect the temperature change in the dense phase, and can reflect the temperature change in the dense phase in the first instance.

[0029] The reaction temperature is automatically controlled by the slide valve. So the slide valve is usually in the open or closing operation all the time. When the slide valve is opened wider, the fresh catalyst entering the regenerator will increase, and the coke amount will also increase, causing the dense-phase concentration in the regenerator to rise and the temperature difference between the dense and dilute phases to become smaller. However, since the amount of low-temperature catalyst entering the dense phase of the regenerator also increases, the dense-phase temperature is reduced. When the slide valve is closed smaller, the dense-phase temperature will decrease, but the amount of low-temperature catalyst entering the regenerator will also decrease, increasing the dense-phase temperature. Therefore, it is in an opposite and counteracting relationship with the dense and dilute phases.

[0030] During normal operation for most of the time, it is stable because the opening and closing range of the slide valve is small, and the temperature difference between the dense and dilute phases is much larger than the counteracting amount. When the opening and closing range of the slide valve increases, the counteracting amount will also increase, even exceeding the change amount in the dense phase, resulting in carbon accumulation. The dense-phase temperature rises to 850 - 950 degrees, then to secondary combustion, the dense-phase temperature drops, and the dilute-phase temperature rises to 850 - 950 degrees. Pushing the slide valve to full open and full close causes carbon accumulation, secondary combustion, carbon accumulation, and repeated cycles.

[0031] The areas where the dense phase is lower than the original dense-phase thermocouple and the dilute phase is higher than the original dilute-phase thermocouple are within the protection scope of this invention patent. Whether the temperature difference between the dense and dilute phases is designed for the same phase or different phases, it is also within the protection scope of this patent.

[0032] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered as within the scope described in this specification. The above-described embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A method for positioning a thermocouple for the temperature difference between the dilute phase and the dense phase in a catalytic cracking regenerator, characterized in that: A thermocouple is provided for each of the dilute-phase regenerator and the dense-phase regenerator. Taking the intersection line of the third quadrant and the fourth quadrant as the reference line, at an angle of plus or minus 30 degrees, and at the midpoint between two adjacent cyclone separators; Height positioning: For the dense-phase thermocouple, at the lower 1 / 3 of the total height of the dense-phase regenerator; Dilute-phase thermocouple positioning: At the same height as the lower edge of the inlet of the cyclone separator; Horizontal positioning: At the midpoint between two adjacent cyclone separators; Height positioning: In the area of the dilute-phase regenerator higher than the original dilute-phase thermocouple and in the area of the dense-phase regenerator lower than the original dense-phase thermocouple.

2. The method for positioning a thermocouple for the temperature difference between the dilute phase and the dense phase of a catalytic cracking regenerator according to claim 1, characterized in that: Simplified version of the dilute-dense phase temperature difference: Without adding new dilute-dense phase thermocouples, change the dense-phase thermocouple of the original dilute-dense phase temperature difference to the dense-phase thermocouple in the third quadrant, and keep the position of the dilute-phase thermocouple of the original dilute-dense phase unchanged.

3. The method for positioning a thermocouple for the temperature difference between the dense phase and the dilute phase in a catalytic cracking regenerator according to claim 1, wherein: Change the dilute-dense phase temperature difference thermocouples to the third quadrant.

4. The method for positioning a thermocouple for the temperature difference between the dilute phase and the dense phase in a catalytic cracking regenerator according to claim 1, characterized in that: The design of the dilute-dense phase temperature difference involves having the same-phase dilute-phase thermometer above the dense-phase thermometer.

5. The thermocouple positioning method for the temperature difference between the dense phase and the dilute phase in the catalytic cracking regenerator according to claim 1, wherein: The design of the dilute-dense phase temperature difference involves different phases, with the dilute-phase thermometer designed diagonally above or directly above the dense-phase thermometer.