Delay coking device sump oil reduction system and process based on contact cooling tower optimization
Patent Information
- Application Number
- CN202510917708.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-03
- Publication Date
- 2025-10-17
AI Technical Summary
The delayed coking unit produces a large amount of waste oil during operation. In the traditional process, the waste oil needs to be recycled through the tank area, which increases the processing cost, reduces the yield of the unit, and has high energy consumption. In addition, the temperature control of the circulating oil at the bottom of the contact cooling tower is insufficient, making it difficult to remove moisture and unable to be directly recycled.
By adding a heater at the bottom of the contact cooling tower to raise the temperature to 150℃~200℃, and adopting a multi-circulation design, including quenching oil recycling, top reflux temperature control and outlet oil circuit, combined with automatic regulating valve group and flow meter, efficient dehydration and separation of waste oil can be achieved, and steam condensate water resources can be reused.
It achieves zero output of waste oil, reduces processing costs, improves recycling efficiency, simplifies processes, increases device yield, reduces energy consumption, and reduces environmental pollution risks.
Smart Images
Figure CN120795946A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of petrochemical industry, and more particularly relates to a delayed coking unit dirty oil reduction system and process based on contact cooling tower optimization. BACKGROUND
[0002] The delayed coking unit is a key equipment for processing heavy oil in the oil refining industry, and a large amount of dirty oil is generated during its operation due to equipment inspection and maintenance and process fluctuations. In the traditional process, dirty oil needs to be recycled through the tank farm, resulting in increased processing costs, reduced unit yield, and problems such as high energy consumption and complex operation. In the prior art, the bottom circulating oil temperature control of the contact cooling tower is insufficient, making it difficult to remove water from the dirty oil, and the dirty oil cannot be directly recycled. Therefore, there is an urgent need for a technical solution that can reduce the output of dirty oil and improve recycling efficiency. SUMMARY
[0003] To solve the above technical problems, the present application provides a delayed coking unit dirty oil reduction system and process based on contact cooling tower optimization to solve the above problems.
[0004] A delayed coking unit dirty oil reduction system based on contact cooling tower optimization, comprising: a contact cooling tower (C-1004) for storing and removing water from dirty oil; a tower bottom heater (E-1026) for heat exchange with circulating oil through 3.5 MPa steam to heat the circulating oil to 150-200℃; a contact cooling tower bottom circulating pump (P-1015) for sending the dehydrated circulating oil in three ways, one of which is used as quenching oil to recycle to the top of the coke drum; a water tank cooler (E-1011) and a tower top water cooler (E-1009) for adjusting the circulating oil temperature; a contact cooling tower top gas-liquid separation tank (D-1006) for separating dirty water and sending it to an acidic water stripping device.
[0005] Preferably, the bottom heater (E-1026) is controlled by the regulating valve group (FV-20606) to maintain the circulating oil temperature in the set range, and the contact cooling bottom circulating oil is divided into three paths after being heated by the heater (E-1026): the first path is returned to the bottom after being heated to 235 DEG C for the second time; the second path is transported to the coke tower top as the quenching oil; the third path is divided into two paths after being cooled by the water tank cooler (E-1011), one path is used as the top reflux, and the other path is sent out of the device, and the system further comprises an air cooler (A-1005) and a tower top water cooler (E-1009) for cooling the tower top water vapor and light hydrocarbons to below 40 DEG C, and the system realizes closed-loop control of the circulating oil flow and the steam flow through the flow meter (FT-20605, FT-20606) and the regulating valve group (FV-20605, FV-20606), and the liquid level of the contact cooling tower top gas-liquid separation tank (D-1006) is controlled by the liquid level regulating valve group (LV-1008, LV-1010), so as to ensure the separation efficiency of the sewage and the sewage.
[0006] A delayed coking device sewage reduction process based on contact cooling tower optimization comprises the following steps: the contact cooling tower bottom circulating oil is heated to 150 DEG C-200 DEG C by the bottom heater (E-1026) to remove water; the dehydrated circulating oil is transported in three paths, one of which is returned to the coke tower top as the quenching oil; the circulating oil temperature is adjusted by the water tank cooler (E-1011) and the tower top water cooler (E-1009) to control the tower top gas phase temperature; the tower top water vapor and light hydrocarbons are cooled and separated sewage, which is sent to the sour water stripping device, the quenching oil return flow is adjusted in real time by the flow meter (FI-20603) and the regulating valve group (FY-20603), the 3.5 MPa steam condensate water is transported to the steam generator (D-1003) as the water source to realize resource recycling, and the process monitors and controls the temperature of the upper part of the lower section of the contact cooling tower by the thermocouple (TI-1013) and the regulating valve group (TV-1013) to ensure the dehydration effect.
[0007] Compared with the prior art, the application has the following beneficial effects:
[0008] By adding the contact cooling tower bottom heater, the circulating oil is heated to 150 DEG C-200 DEG C to efficiently remove water to meet the return-to-refining conditions.
[0009] The multi-path circulating design (including quenching oil return, top reflux temperature control, and device oil path) is adopted to realize sewage "zero output" and significantly reduce the treatment cost.
[0010] The system stability and operation efficiency are improved through the automatic adjustment of the temperature, flow and liquid level (such as the regulating valve group TV-1013, FV-20605, etc.).
[0011] The optimized process reuses 3.5 MPa steam condensate water to the steam generator, reduces energy consumption, and meets the energy saving and consumption reduction requirements.
[0012] The overall process simplifies the waste oil treatment process, improves device yield and economic benefits, and reduces the risk of environmental pollution. BRIEF DESCRIPTION OF DRAWINGS
[0013] Figure 1 is a process flow diagram of the present application. DETAILED DESCRIPTION
[0014] The embodiments of the present application will be further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.
[0015] Please refer to Figure 1 , the present application provides a kind of based on contact cooling tower optimization's waste oil reduction system of delayed coking device, including: contact cooling tower (C-1004), for storing and removing moisture in waste oil;Bottom heater (E-1026), by 3.5 MPa steam and circulating oil heat exchange, circulating oil is heated to 150 ℃~200 ℃;Contact cooling tower bottom circulating pump (P-1015), for the circulating oil after dehydration is sent in three ways, one way as quenching oil back to coke tower top;Water tank cooler (E-1011) and tower top water cooler (E-1009), for adjusting circulating oil temperature;Contact cooling tower top gas-liquid separation tank (D-1006), separate waste water and send to acidic water stripping device.
[0016] Bottom heater (E-1026) controls 3.5 MPa steam flow through regulating valve group (FV-20606) to maintain circulating oil temperature in the set range, contact cooling tower bottom circulating oil is divided into three ways after heater (E-1026): first way returns to bottom after secondary heating to 235 DEG C;Second way as quenching oil is transported to coke tower top;Third way is divided into two ways after cooling through water tank cooler (E-1011), one way as top backflow, another way sends out device, system also includes air cooler (A-1005) and tower top water cooler (E-1009), for cooling tower top water steam and light hydrocarbon to below 40 DEG C, system realizes closed loop control of circulating oil flow and steam flow through flow meter (FT-20605, FT-20606) and regulating valve group (FV-20605, FV-20606), the liquid level of contact cooling tower top gas-liquid separation tank (D-1006) is controlled through liquid level regulating valve group (LV-1008, LV-1010), ensure the separation efficiency of waste water and waste oil.
[0017] A kind of contact cooling tower optimization-based delayed coking unit oil reduction process, comprising the following steps: contact cooling tower bottom circulating oil is heated to 150 DEG C ~ 200 DEG C by bottom heater (E-1026), remove moisture;Dehydrated circulating oil is transported in three ways, one of which is returned to the top of the coke tower as a quenching oil;The temperature of the circulating oil is adjusted by water tank cooler (E-1011) and tower top water cooler (E-1009), and the temperature of the gas phase at the top of the tower is controlled;The tower top water vapor and light hydrocarbon are cooled and separated after separating sewage, and are sent to the acid water stripping device, and the quenching oil return flow is adjusted in real time by flow meter (FI-20603) and regulating valve group (FY-20603), and the 3.5MPa steam condensate is transported to the steam generator (D-1003) as a water source, realizing resource recycling, and the process monitors and controls the temperature of the lower part of the contact cooling tower by thermocouple (TI-1013) and regulating valve group (TV-1013), to ensure the dehydration effect.
[0018] Working principle:
[0019] Temperature regulation and moisture removal
[0020] A heater (E-1026) is added at the bottom of the contact cooling tower (C-1004), and 3.5MPa steam is used for heat exchange with the circulating oil to heat the circulating oil at the bottom of the tower to 150 DEG C ~ 200 DEG C. This temperature range can effectively evaporate the moisture in the oil, so that the circulating oil meets the return conditions. The dehydrated circulating oil is transported by pump (P-1015) in three ways:
[0021] First: after being heated to 235 DEG C, it is returned to the bottom of the tower to maintain the temperature stability in the tower;
[0022] Second: as a quenching oil, it is directly returned to the top of the coke tower to replace the traditional discharged dirty oil, achieving "zero output";
[0023] Third: after being cooled by water tank cooler (E-1011), it is divided into top reflux oil and device oil, which are used to control the temperature of the gas phase at the top of the tower and transport qualified oil products, respectively.
[0024] Gas-liquid separation and sewage treatment
[0025] The water vapor and a small amount of light hydrocarbon removed at the top of the tower are cooled to below 40 DEG C by air cooler (A-1005) and tower top water cooler (E-1009), and enter the gas-liquid separation tank (D-1006). The separated sewage is sent to the acid water stripping device by pump (P-1013) for treatment, and the light hydrocarbon is vented through the gas system to avoid environmental pollution.
[0026] Automatic control and resource recycling
[0027] Temperature and flow closed-loop control: Real-time monitoring and adjustment of circulating oil temperature, steam flow and back-refining amount through thermocouple (TI-1013), flow meter (FT-20605 / 20606) and regulating valve group (TV-1013, FV-20605 / 20606) to ensure stable operation of the system.
[0028] Liquid level balance: The liquid levels of sewage and dirty oil in the gas-liquid separation tank (D-1006) are automatically adjusted by the liquid level regulating valve group (LV-1008, LV-1010) to ensure separation efficiency.
[0029] Energy-saving design: 3.5MPa steam condensate water is transported to the steam generator (D-1003) as a water source, realizing heat energy recovery and resource recycling.
[0030] Process synergy effect
[0031] Through the synergistic effect of multi-path circulation and temperature control, the water in the dirty oil is efficiently removed, and the quality of the back-refined oil meets the standard, avoiding the traditional process of sending dirty oil for treatment. At the same time, the automation system reduces the need for manual intervention, improving the reliability and economic benefits of the process.
[0032] Key innovations:
[0033] Temperature precise control: Two-stage heating (bottom heater + secondary heating) ensures complete dehydration of circulating oil.
[0034] Multi-path circulation design: Realize the integration of dirty oil closed-loop back-refining, temperature control and product output process.
[0035] Efficient use of resources: Steam condensate water recycling and zero dirty oil discharge significantly reduce energy consumption and processing costs. The following is the material balance table of this process:
[0036]
[0037]
[0038] Embodiments of the present application are given for the purpose of example and description, and are not intended to be exhaustive or to limit the application to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Embodiments are chosen and described in order to best explain the principles of the application and its practical application, and to enable others skilled in the art to understand the application for various embodiments with various modifications as are suited to the particular use contemplated.
Claims
1. A delayed coking unit waste oil reduction system based on contact cooling tower optimization, characterized in that: include: Contact cooling tower (C-1004), used to store and remove moisture from dirty oil; The tower bottom heater (E-1026) exchanges heat with the circulating oil through 3.5MPa steam, raising the circulating oil temperature to 150℃~200℃; The contact cooling tower bottom circulation pump (P-1015) is used to transport the dehydrated circulating oil in three routes, one of which is recycled to the top of the coke tower as quenching oil; Water tank cooler (E-1011) and tower top water cooler (E-1009) are used to regulate the circulating oil temperature; The gas-liquid separation tank (D-1006) at the top of the contact cooling tower separates the wastewater and sends it to the acid water stripping device.
2. A delayed coking unit waste oil reduction system based on contact cooling tower optimization according to claim 1, characterized in that: The tower bottom heater (E-1026) controls the 3.5MPa steam flow through the regulating valve group (FV-20606) to maintain the circulating oil temperature within the set range.
3. A delayed coking unit waste oil reduction system based on contact cooling tower optimization according to claim 1, characterized in that: The circulating oil at the bottom of the contact cooling tower is divided into three routes after passing through the heater (E-1026): The first path is heated to 235°C for the second time and then returns to the bottom of the tower; The second route is used as quench oil and is transported to the top of the coke tower; The third route is cooled by the water tank cooler (E-1011) and then divided into two routes, one as top reflux and the other as a delivery device.
4. A delayed coking unit waste oil reduction system based on contact cooling tower optimization according to claim 1, characterized in that: The system also includes an air cooler (A-1005) and a tower top water cooler (E-1009) for cooling the tower top water vapor and light hydrocarbons to below 40°C.
5. A delayed coking unit waste oil reduction system based on contact cooling tower optimization according to claim 1, characterized in that: The system realizes closed-loop control of circulating oil flow and steam flow through flow meters (FT-20605, FT-20606) and regulating valve groups (FV-20605, FV-20606).
6. A delayed coking unit waste oil reduction system based on contact cooling tower optimization according to claim 1, characterized in that: The liquid level of the gas-liquid separation tank (D-1006) at the top of the contact cooling tower is controlled by a liquid level regulating valve group (LV-1008, LV-1010) to ensure the separation efficiency of sewage and waste oil.
7. A delayed coking unit waste oil reduction process based on the system according to any one of claims 1 to 6, characterized in that: The following steps are involved: The circulating oil at the bottom of the contact cooling tower is heated to 150℃~200℃ through the bottom heater (E-1026) to remove moisture; The dehydrated circulating oil is transported in three ways, one of which is recycled to the top of the coke tower as quenching oil; The circulating oil temperature is adjusted by the water tank cooler (E-1011) and the tower top water cooler (E-1009) to control the tower top gas phase temperature; The water vapor and light hydrocarbons at the top of the tower are cooled, the wastewater is separated, and sent to the acid water stripping unit.
8. A delayed coking unit waste oil reduction process based on contact cooling tower optimization as claimed in claim 7, characterized in that: The quench oil recycling flow rate is adjusted in real time by the flow meter (FI-20603) and the regulating valve group (FY-20603).
9. A delayed coking unit waste oil reduction process based on contact cooling tower optimization as claimed in claim 7, characterized in that: The 3.5MPa steam condensate is transported to the steam generator (D-1003) as a water source, thereby realizing resource recycling.
10. A delayed coking unit waste oil reduction process based on contact cooling tower optimization according to claim 7, characterized in that: The process monitors and controls the temperature of the upper part of the lower section of the contact cooling tower through a thermocouple (TI-1013) and a regulating valve group (TV-1013) to ensure the dehydration effect.