JP7064362B2 - Stain evaluation method for heat exchanger for flow contact cracking equipment and stain evaluation device for heat exchanger for flow contact cracking equipment - Google Patents

Description

The present invention relates to a heat exchanger dirt evaluation method and a heat exchanger dirt evaluation device.

Conventionally, heat exchangers have been used in various processing processes, and for example, they have also been used in petroleum refining processes for preheating raw material oil compositions for fluidized catalytic crackers and the like.

A fluid catalytic cracking device (FCC) is a device that cracks heavy oil fractions with large molecular weight into low molecular weight gasoline fractions and intermediate fractions in the petroleum refining process. It is an apparatus for cracking a heavy oil fraction by contacting it with a fluid catalytic cracking catalyst (see, for example, Patent Document 1 (Japanese Unexamined Patent Publication No. 11-10204)).
According to the fluid cracking device, gasoline fractions, etc. can be produced from heavy oil, which is difficult to use as it is due to environmental load, etc., so it is a very important device in the petroleum refining field, and at the same time, it is a limited resource. It is an environment-friendly processing device that can make effective use of.

As the raw material oil to be processed by the fluidized catalytic cracking apparatus, for example, one or more selected from desulfurized heavy oil, thermally cracked cracked heavy oil, indirect cracked heavy oil, direct desulfurized heavy oil and the like are used, and these raw materials are heat exchangers ( In some cases, it is preheated to around 300 ° C. in a heat exchanger and a heating furnace) and then charged into a fluid catalytic cracking apparatus.

Japanese Unexamined Patent Publication No. 11-10204

However, as examined by the present inventor, as described above, the raw material oil to be processed by the fluid cracking apparatus is composed of heavy oil, and therefore, when preheated using a heat exchanger, it is deposited at the heat exchange site. It was found that the heat exchange efficiency tends to decrease due to the adhesion of substances (dirt). When the heat exchange efficiency decreases, the raw material oil charged into the fluid cracking apparatus is not sufficiently heated, and more energy is required for processing with the fluid cracking apparatus. Therefore, it is separately heated in a heating furnace in advance. In addition, if there is no heating furnace, it is necessary to reduce the processing amount of the fluidized cracking cracker, which leads to an increase in production cost and a decrease in productivity.

For this reason, there has been a demand for a method of evaluating the degree to which the raw material oil adheres deposits (dirt) to the heat exchanger prior to distributing the raw material oil to the heat exchanger.
As a method for evaluating the dirt on the heat exchanger, a desktop type dirt evaluation device that heats the raw material oil sent from the raw material oil tank with a heater having a heating unit arranged in the flow pipe of the raw material oil is used. From the degree of decrease in the raw material oil temperature at the outlet of the heater, the degree of adhesion of deposits (dirt) in the heater part, that is, the degree of adhesion of deposits (dirt) in the heat exchange part of the heat exchanger is estimated. The method can be considered.

However, as a result of the examination by the present inventor, it has been found that even if the evaluation is performed using the evaluation device having the above configuration, it is not always likely to correlate with the degree of contamination of the actual machine.

Further, when the evaluation is performed using the above evaluation device, if the raw material oil to be evaluated has a high degree of contamination (high adhesion of deposits), the degree of contamination is low (adhesion of deposits). In order to select the raw material oil (low), it is necessary to replace the raw material oil in the above raw material oil tank and then heat the raw material oil again with a heating heater to re-evaluate, which makes it difficult to perform a quick evaluation. There was a challenge.

Under such circumstances, the present invention provides a heat exchanger stain evaluation method and a heat exchanger stain evaluation device capable of quickly and accurately evaluating the adhesion of stains to a preheating heat exchanger. It is the purpose.

As a result of diligent studies by the present inventor in order to solve the above technical problems, surprisingly, the raw material oil is sent from one of a plurality of raw material oil tanks, and each heating unit is provided in the raw material oil distribution pipe. It is a method of evaluating stains on heat exchangers that are sequentially heated by a plurality of arranged heating heaters, in which the temperature of each heating unit is set by the temperature setting means provided for each of the heating heaters and the raw material oil inlet of each heating heater is used. It has been found that the above object can be achieved by measuring the temperature of the feedstock oil at the feedstock oil outlet, and the present invention has been completed based on this finding.

That is, the present invention
(1) Inside the distribution pipe of the raw material oil having a diameter of 1.5 to 13 mm by sending the raw material oil for the fluidized catalytic cracking device from one of a plurality of raw material oil tanks having a capacity of 0.5 to 10 L. It is a stain evaluation method for a heat exchanger for a fluid cracking apparatus that sequentially heats with a plurality of heaters consisting of heater rods having a length of 100 to 300 mm and a diameter of 3 to 9 mm, each of which has a heating portion arranged therein.
The temperature of each heating unit is set by the temperature setting means provided for each of the heaters, and the temperature of the raw material oil at the raw material oil inlet and the raw material oil outlet of each of the heating heaters is measured .
The degree of contamination is evaluated based on the change over time in the temperature difference of the raw material oil at the raw material oil inlet and the raw material oil outlet in any of the plurality of heaters.
A method for evaluating stains on heat exchangers for fluid cracking crackers , which is characterized by this.
(2 ) The method for evaluating stains on a heat exchanger according to (1 ) above, wherein the raw material oil is distributed while heating at least a part of a distribution pipe that sends out the raw material oil from the raw material oil tank and conveys the raw material oil.
( 3 ) A distribution pipe for raw material oil having a diameter of 1.5 to 13 mm, which is sent from one of a plurality of raw material oil tanks having a capacity of 0.5 to 10 L. It is a stain evaluation device for a heat exchanger for a fluid cracking device that sequentially heats with a plurality of heaters consisting of heater rods having a length of 100 to 300 mm and a diameter of 3 to 9 mm, each of which has a heating part arranged inside.
The heater has a means for measuring the temperature of the raw material oil at the raw material oil inlet and the raw material oil outlet of the heater together with the temperature setting means of the heating unit .
Further having a display means for displaying the temperature difference of the raw material oil at the raw material oil inlet of the heater and the raw material oil outlet of the heater in any of the plurality of heaters over time.
A stain evaluation device for heat exchangers for fluid cracking crackers , which is characterized by this.
(4 ) The stain evaluation device for the heat exchanger according to ( 3) above, further comprising a heating means for heating at least a part of the distribution pipe that sends out the raw material oil from the raw material oil tank and conveys the raw material oil .
Is to provide.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a stain evaluation method for a heat exchanger and a stain evaluation device for a heat exchanger, which can quickly and accurately evaluate the adhesion of stains to a preheating heat exchanger.

It is a schematic diagram explaining the structural example of the dirt evaluation apparatus of the heat exchanger which concerns on this invention. It is a schematic diagram explaining the structural example of the dirt evaluation apparatus of the heat exchanger which concerns on this invention. It is a figure which shows the relationship between the amount of dirt | adhesion to the dirt evaluation apparatus, and ΔT.

In the stain evaluation method of the heat exchanger according to the present invention, the raw material oil is sent from one of a plurality of raw material oil tanks, and the raw material oil is sequentially heated by a plurality of heating heaters each having a heating unit arranged in the distribution pipe of the raw material oil. This is a method for evaluating stains on a heat exchanger, in which the temperature of each heating unit is set by a temperature setting means provided for each of the heaters, and the temperature of the raw material oil at the raw material oil inlet and the raw material oil outlet of each of the heaters. It is characterized by measuring.

Hereinafter, the method for evaluating the stain on the heat exchanger according to the present invention will be described with reference to the drawings as appropriate.

In the heat exchanger stain evaluation method according to the present invention, as the heat exchanger stain evaluation device, the raw material oil sent from any of a plurality of raw material oil tanks is heated in the raw material oil distribution pipe. A stain evaluation device that sequentially heats with a plurality of heating heaters in which a section is arranged, wherein the heating heater measures the raw material oil temperature at the raw material oil inlet and the raw material oil outlet of the heating heater together with the temperature setting means of the heating section. Use what you have.

In the heat exchanger dirt evaluation method according to the present invention, the heat exchanger dirt evaluation device has a plurality of raw material oil tanks.
The number of the feedstock oil tanks is not particularly limited, but 2 to 5 is suitable, 2 to 4 is more suitable, and 2 to 3 is more suitable.
In the example shown in FIG. 1, the dirt evaluation device E has two raw material oil tanks T1 and T2.

Since the number of raw material oil tanks is within the above range, even if there are many raw material oil types to be evaluated, the raw materials to be distributed in the evaluation device without replacing the raw material oil in the raw material oil tanks. The raw material oil can be evaluated easily in a short time only by switching the oil as appropriate.

The content of each raw material oil tank is not particularly limited, but is preferably 0.5 to 10 L, more preferably 0.5 to 8 L, and even more preferably 0.5 to 6 L.
Each raw material oil tank may have the same content or may have a different content.
Since the content of the raw material oil tank is within the above range, it is possible to easily and quickly evaluate the dirt while reducing the size of the dirt evaluation device such as on the table.

The raw material oil stored in the raw material oil tank is not particularly limited, and examples thereof include raw material oil for a fluidized catalytic cracking apparatus. Raw material oils for fluidized catalytic crackers include one or more raw material oil base materials selected from desulfurized heavy oil, thermal decomposition desulfurized heavy oil, indirect desulfurized heavy oil, direct desulfurized heavy oil, etc., and one or more raw material oil base materials. In addition, those containing an antifouling agent can be mentioned.

In the stain evaluation method of the heat exchanger according to the present invention, the raw material oil tank preferably has a heating means capable of preheating the internal raw material oil.
For example, as illustrated in FIG. 1, it is preferable that the raw material oil tank T1 or T2 can heat the raw material oil in advance by a separately installed hot plate HP.
When the raw material oil is preheated by the heating means provided in the raw material oil tank, for example, it is preferable to heat the raw material oil to 40 to 80 ° C.

The raw material oil tank has the above heating means, and by preheating the raw material oil in the raw material oil tank by the heating means and then sending it out, the raw material oil is stably and in a short time in the heating heater described later. Since it can be heated to a desired temperature, the raw material oil can be evaluated quickly, stably and easily.

In the stain evaluation method of the heat exchanger according to the present invention, the raw material oil is sent from any of a plurality of tanks, and in the example shown in FIG. 1, the raw material oil is distributed from any of the raw material oil tanks T1 and T2. It is sent through c.

The selection or switching of the raw material oil tank for the distribution pipe, that is, the selection or switching of the raw material oil to be evaluated, is performed by using a switching valve (switching valve VL1 for delivery in the example shown in FIG. This can be done by switching the oil tank.

The diameter of the distribution pipe for delivering and transporting the raw material oil from the raw material oil tank is preferably 1.5 to 13 mm, more preferably 3 to 13 mm, further preferably 3 to 9 mm, still more preferably 3 to 7 mm.

Since the diameter of the distribution pipe is within the above range, even if the raw oil contains impurities such as metal components, the raw oil can be removed from the raw oil tank without causing clogging or blockage in the pipes. It can be stably sent and transported.

The transport flow rate of the feedstock delivered from any one selected from the plurality of feedstock tanks and transported in the apparatus is preferably 3 to 18 mL / min, more preferably 5 to 15 mL / min. 8-13 mL / min is even more preferred.

Since the transport speed of the feedstock is within the above range, quick and simple evaluation can be performed, and the feedstock can be stably delivered from the feedstock tank without causing clogging or blockage in the piping, etc., which will be described later. While the raw material oil is suitably heated by the heating heater, the heated raw material oil can be stably returned to the raw material tank.

The feedstock is delivered from the feedstock tank to the distribution pipe, and the feed and transport of the feedstock that is transported in the apparatus is usually provided in one of the feedstock distribution routes (symbol in the example shown in FIG. 1). It is done by a pump (represented by P).

The pump preferably has a maximum discharge rate of 0.2 to 5 L / hour, more preferably 0.5 to 4 L / hour, and even more preferably 1 to 3 L / hour.

Since the maximum discharge amount of the pump is within the above range, quick and simple evaluation can be performed, and the raw oil can be stabilized from the raw oil tank without causing clogging or blockage in the piping or the like. The raw material oil can be suitably heated by the heating heater described later.

In the heat exchanger dirt evaluation method according to the present invention, the heat exchanger dirt evaluation device may further include a heating means for heating at least a part of the distribution pipe that sends out the raw material oil from the raw material oil tank and conveys the raw material oil. preferable.
The heating means for heating the distribution pipe is preferably provided in at least a part of the distribution pipe from the raw material oil tank to just before the inflow to the heater, and until just before being sent from the raw material oil tank and flowing into the heater. It is preferable that it is provided in the entire distribution pipe of.

Examples of the heating means for the distribution pipe include one or more selected from ribbon heaters, jacket heaters, and the like.

When the raw material oil is preliminarily heated by the heating means provided in the distribution pipe, it is preferably heated to, for example, 40 to 100 ° C.

Since the distribution pipe has the above-mentioned heating means, the raw material oil can be stably and quickly heated to a desired temperature in the heating heater described later, so that the raw material oil can be evaluated quickly, stably and easily. can.

In the stain evaluation method of the exchanger according to the present invention, when the raw material oil sent from the raw material oil tank is sequentially heated by a plurality of heating heaters each having a heating unit arranged in the flow pipe of the raw material oil, the heating is performed. The temperature of each heating unit is set by the temperature setting means provided for each heater, and the temperature of the raw material oil at the raw material oil inlet and the raw material oil outlet of each heating heater is measured.

Examples of the heating unit constituting the heating heater include a heater rod.
Examples of the material of the heater rod include one or more selected from stainless steel such as SUS316.
When the heating portion constituting the heater is made of a heater rod, the length thereof is preferably 100 to 300 mm, more preferably 150 to 250 mm, still more preferably 180 to 220 mm.
When the heating portion constituting the heating heater is made of a heater rod, the diameter thereof is preferably 3 to 9 mm, more preferably 4 to 8 mm, and further preferably 5 to 7 mm.
When the size of the heater rod is within the above range, it is possible to easily and quickly evaluate the dirt while reducing the size of the dirt evaluation device such as desktop.
The heating portions provided in each of the plurality of heaters may be the same or different.

In the heat exchanger stain evaluation method according to the present invention, the number of heaters constituting the heat exchanger stain evaluation device is preferably 2 to 6, and more preferably 2 to 5. It is appropriate, and it is more appropriate to have 2 to 3 pieces.

In the stain evaluation method for the heat exchanger according to the present invention, the stain evaluation device has a plurality of heaters, so that the raw material oil correlated with the degree of contamination of the actual machine (actual heat exchanger) can be easily evaluated. be able to.

In the stain evaluation method of the heat exchanger according to the present invention, the raw material oil is heated to a desired temperature by the temperature setting means provided for each of the heating heaters.
When heating is performed by the temperature setting means provided in the heater, the set temperature is preferably, for example, 70 to 400 ° C.

In the stain evaluation method of the heat exchanger according to the present invention, the plurality of heaters constituting the stain evaluation device measure the raw material oil temperature at the raw material oil inlet and the raw material oil outlet of the heater together with the temperature setting means of the heating unit. It has means, and the temperature of each heating unit is set by the temperature setting means provided for each of the heating heaters, and the raw material oil temperature at the raw material oil inlet and the raw material oil outlet of each heating heater is measured.

In the example shown in FIG. 1, the dirt evaluation device E has a plurality of heaters HT1 and HT2, each having a heater rod R, and the heaters HT1 and HT2 are each (not shown) the temperature of a heating unit. It has a raw material oil temperature measuring means (TM1 _IN and TM2 _IN ) arranged at the raw material oil inlet of the heater and a raw material oil temperature measuring means (TM1 _OUT and TM2 _OUT ) arranged at the raw material oil outlet, respectively, together with the setting means. are doing.
Then, the temperature of the heating unit is set by the temperature setting means provided for each of the heating heaters HT1 and HT2, and the raw material oil temperature is measured at the raw material oil inlet and the raw material oil outlet of the heating heaters HT1 and HT2, respectively. The raw material oil temperature is measured by means.

In the stain evaluation method of the heat exchanger according to the present invention, the raw material oil outlet of the heating heater (HT1 in the example of FIG. 1) arranged on the upstream side and the subsequent heating heater (HT2 in the example of FIG. 1) arranged on the downstream side. ) When the distribution pipe between the raw material oil inlet and the raw material oil inlet is heated by a heating means or the like and reaches a certain temperature, the raw material oil temperature at the raw material oil outlet of the upstream heating heater and the subsequent raw material oil of the downstream heating heater When it is considered that the temperature is the same as the raw material oil temperature at the inlet, the raw material oil temperature measuring means (TM1 _OUT in the example of FIG. 1) at the raw material oil outlet of the heater arranged on the upstream side is arranged on the downstream side. The raw material oil temperature measuring means (TM2 _IN in the example of FIG. 1) at the raw material oil inlet of the heating heater may not be installed, but only one of them may be installed.

In the stain evaluation method of the heat exchanger according to the present invention, the temperature difference between the temperatures of the raw material oil at the raw material oil inlet and the raw material oil outlet of the heater in any of the above-mentioned plurality of heaters is calculated, and the change over time is used. The degree of dirt can be evaluated based on this.
In the stain evaluation method for the heat exchanger according to the present invention, the stain evaluation device changes the temperature difference between the raw material oil inlet of the heater and the raw material oil outlet of the heater in any of the plurality of heaters over time. It may further have a display means for displaying the target, and the change with time can be easily observed by using the display means.

In the above evaluation, as a result of deposits (dirt) adhering to the heating part of the heating heater due to the raw material oil and it becomes impossible to sufficiently heat, the raw material oil temperature T ₂ at the heater outlet is set to the raw material oil temperature T ₁ at the heater inlet. This is based on the fact that the temperature difference ΔT represented by T ₂ − T ₁ becomes smaller with time because the temperature cannot be raised sufficiently.
That is, when the raw material oil temperature and the raw material oil distribution speed in the raw material oil tank, the distribution pipe, and the heating heater are constant, if the raw material oil does not easily adhere to the heating part of the heating heater, the above T2 _- T. While the temperature difference ΔT represented by ₁ is unlikely to change over time, if the raw material oil is such that dirt easily adheres to the heating part of the heater, the temperature difference ΔT represented by T ₂ − T ₁ above.
Since T tends to decrease with time, the degree of adhesion of dirt to the heat exchanger can be evaluated based on the change of ΔT with time.

In FIG. 3, the raw material oil composition for a fluidized catalytic decomposition apparatus is sent from the raw material oil tank T1 to the flow pipe at a flow rate of 10 mL / min using the evaluation device illustrated in FIG. A heating heater when the operation of sequentially heating with a plurality of heating heaters HT1 and HT2 in which a SUS316 heater rod having a length of 200 mm and a diameter of 6 mm is arranged as a heating part and returning the oil to the raw material oil tank T1 is performed for 1000 minutes. The temperature difference ΔT (° C.) expressed by the “raw material oil temperature T ₂ (° C.) at the heater outlet and the raw material oil temperature T ₁ (° C.) at the heater inlet) with respect to the amount of dirt adhering (mg) in the heating part of the HT1 and the heating heater HT2. It is a figure which shows the relationship of.
As shown in FIG. 3, the raw material oil temperature T ₁ (° C) at the heater inlet is kept constant, and the raw material oil temperature T ₂ (° C) at the heater outlet is measured with the set temperature of the heater constant as the above temperature. When the difference ΔT (° C.) was obtained and the relationship with the dirt adhesion in the heating part of the heater was obtained, the dirt adhesion amount (mg) in the heating part of the heater and the temperature difference ΔT had a correlation, and the dirt adhered. Since ΔT (° C.) also increases as the amount increases, it can be seen that the degree of adhesion of dirt to the heated portion of the heat exchanger can be evaluated by measuring the above ΔT.

The raw material oil heated by the heater of the heating unit may be returned to the raw material tank of the sending source, or may be separately discharged to the outside of the system.
In the evaluation device E shown in FIG. 1, by switching the switching valve VL2, the raw material oil heated by the heater of the heating unit can be appropriately returned to the raw material oil tank of the sending source.
Further, FIG. 2 shows an aspect in which the evaluation device E shown in FIG. 1 further has a distribution pipe for discharging raw material oil to the outside of the system provided with a switching valve VL3, and in the embodiment shown in FIG. The raw material oil heated by the heating heater can be discharged to a waste oil tank or the like provided outside the system by appropriately switching the switching valve VL3.

In the stain evaluation method of the heat exchanger according to the present invention, the operation of sending the raw material oil from the raw material oil tank, transporting it, and heating it with a heater can be repeated over a certain period of time, but in this case, it depends on the change with time. In comparing the degree of adhesion of dirt, it is preferable to keep the measurement conditions such as the raw material oil temperature and the raw material oil distribution speed in the raw material oil tank, the distribution pipe and the heater constant.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for evaluating stains on a heat exchanger that can quickly and accurately evaluate the adhesion of stains to a preheating heat exchanger.

Next, a stain evaluation device for the heat exchanger according to the present invention will be described.
In the stain evaluation device of the heat exchanger according to the present invention, the raw material oil sent from any of the plurality of raw material oil tanks is sequentially charged by a plurality of heating heaters each having a heating unit arranged in the raw material oil distribution pipe. It is a stain evaluation device of a heat exchanger to be heated, and is characterized in that the heating heater has a means for measuring the raw material oil temperature at the raw material oil inlet and the raw material oil outlet of the heating heater together with the temperature setting means of the heating unit. It is a thing.
The details of the stain evaluation device for the heat exchanger according to the present invention are as described above.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a heat exchanger stain evaluation device capable of quickly and accurately evaluating the adhesion of stains to a preheating heat exchanger.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a stain evaluation method for a heat exchanger and a stain evaluation device for a heat exchanger, which can quickly and accurately evaluate the adhesion of stains to a preheating heat exchanger.

E: Dirt evaluation device T1, T2: Raw material oil tank VL1, VL2, VL3: Switching valve HP: Hot plate c: Distribution pipe HT1, HT2: Heater R: Heater rod

Claims (4)

The raw material oil for the fluidized cracking cracker is sent out from one of a plurality of raw material oil tanks having a capacity of 0.5 to 10 L, and heated in the flow pipe of the raw material oil having a diameter of 1.5 to 13 mm. It is a stain evaluation method for a heat exchanger for a fluid cracking apparatus that sequentially heats with a plurality of heaters consisting of heater rods having a length of 100 to 300 mm and a diameter of 3 to 9 mm in which parts are arranged.
The temperature of each heating unit is set by the temperature setting means provided for each of the heaters, and the temperature of the raw material oil at the raw material oil inlet and the raw material oil outlet of each of the heating heaters is measured .
The degree of contamination is evaluated based on the change over time in the temperature difference of the raw material oil at the raw material oil inlet and the raw material oil outlet in any of the plurality of heaters.
A method for evaluating stains on a heat exchanger for a fluidized cracking cracker . The stain evaluation method for a heat exchanger according to claim 1, wherein the raw material oil is distributed while heating at least a part of a distribution pipe that sends out the raw material oil from the raw material oil tank and conveys the raw material oil. The raw material oil for the fluidized catalytic cracking device, which is sent from one of a plurality of raw material oil tanks having a capacity of 0.5 to 10 L, is placed in the flow pipe of the raw material oil having a diameter of 1.5 to 13 mm. It is a stain evaluation device for a heat exchanger for a fluid cracking device that sequentially heats with a plurality of heaters consisting of heater rods having a length of 100 to 300 mm and a diameter of 3 to 9 mm in which a heating unit is arranged.
The heater has a means for measuring the temperature of the raw material oil at the raw material oil inlet and the raw material oil outlet of the heater together with the temperature setting means of the heating unit .
Further having a display means for displaying the temperature difference of the raw material oil at the raw material oil inlet of the heater and the raw material oil outlet of the heater in any of the plurality of heaters over time.
A stain evaluation device for heat exchangers for fluid cracking crackers . The stain evaluation device for a heat exchanger according to claim 3 , further comprising a heating means for heating at least a part of a distribution pipe that sends out raw material oil from the raw material oil tank and conveys the raw material oil .

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