Heavy crude oil electric desalting device

Abstract

The utility model belongs to the technical field of electro-desalting, and particularly relates to a heavy crude oil electro-desalting device. Comprising a crude oil heat exchanger before removal, a first electric desalting tank, a second electric desalting tank, a third electric desalting tank, a crude oil heat exchanger after removal and a flash tower which are connected in sequence, and further comprises a fourth electric desalting tank and a fifth electric desalting tank which are connected with the first electric desalting tank and the second electric desalting tank in parallel, inlets of the first electric desalting tank, the second electric desalting tank, the third electric desalting tank, the fourth electric desalting tank and the fifth electric desalting tank are provided with water injection pipelines, the inlets of the first electric desalting tank and the fourth electric desalting tank are also provided with crude oil flow regulating valves, and an inlet pipeline of the crude oil heat exchanger before desalting is connected with a demulsifying agent pipeline. Through the multi-stage electric desalting treatment and intelligent response control technology, the desalting efficiency is remarkably improved, the energy consumption is reduced, the service life of equipment is prolonged, the operation process is simplified, the adaptability of the device is enhanced, and efficient, energy-saving, durable and easy-to-operate crude oil desalting treatment is realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of electric desalting, and particularly relates to a heavy crude oil electric desalting device. BACKGROUND

[0002] In the petroleum refining industry, the processing of heavy crude oil is a crucial link. Because heavy crude oil contains a large amount of salt, water and other impurities, these impurities will have an adverse effect on equipment and products in the subsequent processing process. Therefore, before the crude oil enters the oil refining device, effective desalting treatment must be carried out.

[0003] Traditional heavy crude oil desalting devices usually use a single electric desalting tank for treatment. This treatment method has the problems of low treatment efficiency, incomplete salt removal, etc. In order to improve the desalting efficiency, some improved heavy crude oil desalting devices use multiple electric desalting tanks in series or parallel. However, these devices often have problems such as uneven distribution of crude oil flow, difficulty in accurately controlling the amount of water injection and the amount of demulsifier, etc. during operation, resulting in unstable desalting effect and high energy consumption.

[0004] In addition, the existing heavy crude oil desalting device also has deficiencies in monitoring and control. For example, there is a lack of real-time monitoring means for the crude oil inlet, outlet and each processing stage, so that the operating personnel cannot timely understand the running state of the device and it is difficult to make targeted adjustments and optimization. Therefore, it is necessary to improve the existing heavy crude oil desalting device to improve its desalting efficiency, stability and energy consumption performance, and to strengthen the monitoring and control means to realize the intelligent operation of the device. SUMMARY

[0005] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a heavy crude oil electric desalting device, which significantly improves the desalting efficiency, reduces the energy consumption, prolongs the service life of the equipment, simplifies the operation process, enhances the adaptability of the device, and realizes efficient, energy-saving, durable and easy-to-operate crude oil desalting treatment.

[0006] The utility model is implemented by adopting the following technical solutions:

[0007] The heavy crude oil electric desalting device comprises, in sequence, a pre-desalting crude oil heat exchanger, a first electric desalting tank, a second electric desalting tank and a third electric desalting tank, a post-desalting crude oil heat exchanger and a flash tower, and further comprises a fourth electric desalting tank and a fifth electric desalting tank connected in parallel with the first electric desalting tank and the second electric desalting tank, and the inlet of each of the first electric desalting tank, the second electric desalting tank, the third electric desalting tank, the fourth electric desalting tank and the fifth electric desalting tank is provided with a water injection pipeline, the inlet of the first electric desalting tank and the fourth electric desalting tank is further provided with a crude oil flow regulating valve, and a demulsifier pipeline is connected to the inlet pipeline of the pre-desalting crude oil heat exchanger.

[0008] The first, second, third, fourth and fifth electric desalting tanks are intelligent response control electric desalting tanks.

[0009] The crude oil inlet of the pre-desalting crude oil heat exchanger is connected to the heavy crude oil temporary storage tank through a pipeline, and a demulsifier pipeline is arranged on the pipeline between the heavy crude oil temporary storage tank and the pre-desalting crude oil heat exchanger.

[0010] The heavy crude oil temporary storage tank and the outlet pipeline of the post-desalting crude oil heat exchanger are respectively provided with detection devices.

[0011] The water injection pipeline is provided with a water amount adjusting valve, and the demulsifier pipeline is provided with a metering pump.

[0012] The control system is electrically connected with the crude oil flow adjusting valve, the detection device, the water amount adjusting valve, the metering pump, and the first, second, third, fourth and fifth electric desalting tanks.

[0013] The heavy crude oil electric desalting device has the following working principle:

[0014] The heavy crude oil (with an initial temperature of about 50℃) is first extracted from the heavy crude oil temporary storage tank, and before the crude oil enters the pre-desalting crude oil heat exchanger, the demulsifier added through the demulsifier pipeline is mixed. The addition of demulsifier helps to destroy the emulsified state in the crude oil and promotes the subsequent oil-water separation process. The amount of demulsifier added is accurately controlled by the metering pump, and this adjustment is based on the preliminary settlement and dehydration time of the heavy crude oil in the temporary storage tank and the real-time data provided by the subsequent detection device.

[0015] The crude oil mixed with the demulsifier then enters the pre-desalting crude oil heat exchanger, where the crude oil is heated to an appropriate temperature of 140-150℃ to improve the flowability and desalting efficiency of the crude oil. The heated crude oil enters the water injection mixing stage through a pipeline, and each pipeline entering the electric desalting tank is equipped with a water injection pipeline for injecting a certain amount of water into the crude oil. The amount of water injection is accurately controlled by the water amount adjusting valve to ensure the formation of an appropriate oil-water ratio in each electric desalting tank, thereby optimizing the desalting effect.

[0016] The crude oil is divided into two ways after injecting water and enters the electric desalting system: one way passes through the first electric desalting tank and the second electric desalting tank for serial desalting; the other way passes through the fourth electric desalting tank and the fifth electric desalting tank for parallel desalting in series. The two ways of electric desalting tanks adopt intelligent response control technology, which can be remotely monitored and dynamically controlled in real time in the control room (DCS system or PLC cabinet). By changing the operating parameters and output voltage characteristic curve of the transformer online, the high voltage input to the electrode plate in the tank can be accurately controlled, so that the electric field conditions are optimized and the desalting efficiency is improved.

[0017] In the electric desalting tank, the crude oil is separated and settled under the action of the demulsifier and the electric field. The inorganic salt in the crude oil is dissolved in water and removed with the water, so that oil-water separation and inorganic salt removal are realized. The crude oil after parallel connection is desalted with the third electric desalting tank in series, forming a three-stage electric desalting process. This three-stage desalting design can ensure that the salt in the crude oil is fully removed.

[0018] After the three-stage desalting treatment, the crude oil enters the post-crude oil heat exchanger, and is further heated and enters the flash tower for subsequent treatment. Detection devices are installed on the outlet pipelines of the pre-crude oil heat exchanger and the post-crude oil heat exchanger for real-time monitoring of the temperature, pressure and salt content of the crude oil. These parameters provide feedback signals for the control system, so that the control system can adjust the opening of the metering pump, the crude oil flow regulating valve and the water regulating valve according to the real-time data, so as to realize accurate control of the whole desalting process.

[0019] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0020] (1) The heavy crude oil electric desalting device adopts three-stage electric desalting treatment, and the crude oil is subjected to electric field action for multiple times, so that the salt and impurities in the crude oil can be more fully removed, thereby improving the desalting efficiency;

[0021] (2) The heavy crude oil electric desalting device adjusts the addition amount of demulsifier, the crude oil flow and the water injection amount according to real-time data through intelligent response control technology, optimizes the electric field conditions, and reduces energy consumption while ensuring desalting effect;

[0022] (3) The heavy crude oil electric desalting device reduces the corrosion and pollution inside the equipment through the application of multi-stage electric desalting treatment and intelligent response control technology, thereby prolonging the service life of the equipment;

[0023] (4) The heavy crude oil electric desalting device has intelligent control, realizes remote monitoring and real-time dynamic control, simplifies the operation process and reduces the operation difficulty, and has strong adaptability as the device can be adjusted and optimized according to different types of heavy crude oil and different process requirements. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic view of the heavy crude oil electric desalting device.

[0025] In the figure: 1, pre-desalting crude oil heat exchanger; 2, first electric desalting tank; 3, second electric desalting tank; 4, third electric desalting tank; 5, post-desalting crude oil heat exchanger; 6, flash tower; 7, fourth electric desalting tank; 8, fifth electric desalting tank; 9, water injection pipeline; 10, crude oil flow regulating valve; 11, demulsifier pipeline; 12, heavy crude oil temporary storage tank; 13, detection device; 14, water flow regulating valve; 15, metering pump. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme of the utility model more clearly, in the following, to the utility model, make further detailed description with the aid of the drawings.

[0027] Example 1

[0028] As Figure 1 Indicated, the heavy crude oil electric desalting device, including the pre-desalting crude oil heat exchanger 1, first electric desalting tank 2, second electric desalting tank 3 and third electric desalting tank 4, post-desalting crude oil heat exchanger 5 and flash tower 6 that are connected in sequence, still include the fourth electric desalting tank 7 and the fifth electric desalting tank 8 that are connected in parallel with first electric desalting tank 2 and second electric desalting tank 3, the inlet of first electric desalting tank 2, second electric desalting tank 3, third electric desalting tank 4, fourth electric desalting tank 7 and fifth electric desalting tank 8 are equipped with water injection pipeline 9, and the inlet of first electric desalting tank 2 and fourth electric desalting tank 7 is further provided with crude oil flow regulating valve 10, and the inlet pipeline of pre-desalting crude oil heat exchanger 1 is connected with demulsifier pipeline 11.

[0029] First electric desalting tank 2, second electric desalting tank 3, third electric desalting tank 4, fourth electric desalting tank 7 and fifth electric desalting tank 8 are all intelligent response control electric desalting tanks.

[0030] The crude oil inlet of pre-desalting crude oil heat exchanger 1 is connected to heavy crude oil temporary storage tank 12 through a pipeline, and demulsifier pipeline 11 is arranged on the pipeline between heavy crude oil temporary storage tank 12 and pre-desalting crude oil heat exchanger 1.

[0031] Detection device 13 is installed on the outlet pipeline of heavy crude oil temporary storage tank 12 and post-desalting crude oil heat exchanger 5 respectively.

[0032] The water injection pipeline 9 is provided with a water flow regulating valve 14, and the demulsifier pipeline 11 is provided with a metering pump 15.

[0033] The control system is electrically connected with the crude oil flow regulating valve 10, the detection device 13, the water flow regulating valve 14, the metering pump 15, and the first electric desalter 2, the second electric desalter 3, the third electric desalter 4, the fourth electric desalter 7 and the fifth electric desalter 8.

[0034] In operation, the specific steps are as follows:

[0035] The heavy crude oil (with an initial temperature of 50℃) is extracted from the heavy crude oil temporary storage tank 12 and mixed with the demulsifier added through the demulsifier pipeline 11, and the addition amount of the demulsifier is accurately controlled by the metering pump 15. The crude oil mixed with the demulsifier then enters the pre-desalted crude oil heat exchanger 1 for heat exchange, and the crude oil is heated to 150℃. The heated crude oil enters the water injection mixing stage through the pipeline, and a certain amount of water is injected into the crude oil through the water injection pipeline 9, and the water injection amount is accurately controlled by the water flow regulating valve 14.

[0036] The crude oil is divided into two routes after the water injection and enters the electric desalter system: one route sequentially passes through the first electric desalter 2 and the second electric desalter 3 for series desalting; the other route passes through the fourth electric desalter 7 and the fifth electric desalter 8 for series treatment in parallel desalting. Both of the two routes of electric desalters adopt intelligent response control technology, which can be remotely monitored and dynamically controlled in real time in the control room (DCS system or PLC cabinet). By changing the operating parameters and output voltage characteristic curve of the on-line transformer, the high voltage input to the electrode plate in the tank can be accurately controlled, so as to optimize the electric field conditions and improve the desalting efficiency.

[0037] In the electric desalter, the crude oil is subjected to sedimentation and separation under the action of the demulsifier and the electric field, and the two routes of parallel crude oil are subjected to series desalting with the third electric desalter 4, forming a three-stage electric desalting treatment. The crude oil subjected to the three-stage desalting treatment enters the post-desalted crude oil heat exchanger 5, is further heated, and then flows into the flash tower 6 for subsequent processing. The outlet pipelines of the pre-desalted crude oil heat exchanger 1 and the post-desalted crude oil heat exchanger 5 are both provided with detection devices 13, which can monitor the temperature, pressure and salt content of the crude oil in real time, and these parameters provide feedback signals for the control system. The control system dynamically adjusts the opening degrees of the metering pump 15, the crude oil flow regulating valve 10 and the water flow regulating valve 14 according to the real-time data, so as to realize fine control of the entire desalting process.

Claims

1. A heavy crude oil electro-desalting unit characterized by, The device comprises, in sequence, a pre-deparaffinization crude oil heat exchanger (1), a first electric desalting tank (2), a second electric desalting tank (3), a third electric desalting tank (4), a post-deparaffinization crude oil heat exchanger (5), and a flash tower (6), further comprising a fourth electric desalting tank (7) and a fifth electric desalting tank (8) connected in parallel with the first electric desalting tank (2) and the second electric desalting tank (3), and the inlet of each of the first electric desalting tank (2), the second electric desalting tank (3), the third electric desalting tank (4), the fourth electric desalting tank (7), and the fifth electric desalting tank (8) is equipped with a water injection pipeline (9), and the inlet of the first electric desalting tank (2) and the fourth electric desalting tank (7) is further provided with a crude oil flow regulating valve (10), and the inlet pipeline of the pre-deparaffinization crude oil heat exchanger (1) is connected with a demulsifier pipeline (11).

2. The heavy crude oil electro-desalting apparatus of claim 1, wherein, The first electric desalting tank (2), the second electric desalting tank (3), the third electric desalting tank (4), the fourth electric desalting tank (7), and the fifth electric desalting tank (8) are all intelligent response control electric desalting tanks.

3. The heavy crude oil electro-desalting apparatus of claim 2, wherein, The crude oil inlet of the pre-deparaffinization crude oil heat exchanger (1) is connected to a heavy crude oil temporary storage tank (12) through a pipeline, and the demulsifier pipeline (11) is arranged on the pipeline between the heavy crude oil temporary storage tank (12) and the pre-deparaffinization crude oil heat exchanger (1).

4. The heavy crude oil electro-desalting apparatus as claimed in claim 3, wherein, The heavy crude oil temporary storage tank (12) and the outlet pipeline of the post-deparaffinization crude oil heat exchanger (5) are both respectively provided with a detection device (13).

5. The heavy crude oil electro-desalting apparatus as claimed in claim 4, wherein, The water injection pipeline (9) is provided with a water amount regulating valve (14), and the demulsifier pipeline (11) is provided with a metering pump (15).

6. The heavy crude oil electro-desalting apparatus as claimed in claim 5, wherein, The device further comprises a control system, which is electrically connected with the crude oil flow regulating valve (10), the detection device (13), the water amount regulating valve (14), the metering pump (15), and the first electric desalting tank (2), the second electric desalting tank (3), the third electric desalting tank (4), the fourth electric desalting tank (7), and the fifth electric desalting tank (8).

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