Crude oil gradient heating energy-saving system

Abstract

The utility model relates to the technical field of oil refining, in particular to a crude oil gradient heating energy-saving system which comprises a condensate water tank, a primary heat exchanger, a secondary heat exchanger, a cooling water tank and a crude oil conveying pipe. A gas outlet of the gas-water separator is connected with a steam supply pipe through a high-temperature gas pipe I, and a liquid outlet of the gas-water separator is connected with a condensate water tank; a first-stage preheating pipe, a first-stage backflow pipe, a second-stage preheating pipe and a second-stage backflow pipe are sequentially arranged on the crude oil conveying pipe in the crude oil conveying direction, and the first-stage preheating pipe and the first-stage backflow pipe are sequentially connected with a refrigerant inlet and a refrigerant outlet of the first-stage heat exchanger respectively. The second-stage preheating pipe and the second-stage backflow pipe are sequentially connected with a refrigerant inlet and a refrigerant outlet of the second-stage heat exchanger respectively. The crude oil storage tank reduces heating time of crude oil in the storage tank, avoids temperature stratification, improves sedimentation, dehydration and desalination effects of the crude oil, recovers heat of condensate water, saves steam usage amount and saves energy.

Description

Technical Field

[0001] This utility model relates to the field of oil refining technology, specifically to a crude oil gradient heating energy-saving system. Background Technology

[0002] Currently, oil refineries mainly use external floating roof tanks to store crude oil. After heating and dehydrating the crude oil to meet the processing requirements of the unit, it is pumped to the oil refining unit for further processing. However, the following problems exist in the crude oil heating and dehydration process:

[0003] (1) Traditional in-tank heating coils have low heating efficiency and require a large amount of steam. When the number of crude oil storage tanks is small and the crude oil inventory is low, it is impossible to effectively heat and dehydrate the crude oil.

[0004] (2) When heating coils are used for heating, the crude oil in the middle and lower part of the storage tank is mainly heated, and the upper part of the crude oil tank cannot be effectively heated, resulting in "stratification" of crude oil temperature in the storage tank. When crude oil with uneven temperature is sent to the processing unit, it is easy to cause fluctuations in the unit.

[0005] The oil storage and transportation workshop is equipped with a condensate tank. The condensate in the tank mainly comes from the steam heaters of the heavy feedstock tank area, heavy oil tank area, and asphalt tank area, as well as the crude oil transfer heaters. Condensate from the heavy oil pipeline's heat tracing lines flows into the condensate tank via a condensate pipe. The condensate in the tank can be used by the circulating water system and condensate tanks in the drainage workshop. The external condensate temperature from the heavy oil tank area can reach 121-125℃, and the external condensate temperature from the asphalt tank area can reach 120℃. The condensate temperature in the tank can also reach 95℃. A large amount of steam generated in the condensate tank is vented from the top, resulting in the waste of energy as the heat from the steam and the high-temperature condensate is not utilized. Utility Model Content

[0006] The technical problem to be solved by this utility model is to propose a crude oil gradient heating energy-saving system, which reduces the heating time of crude oil in the storage tank, avoids temperature stratification, improves the sedimentation, dehydration and desalination effect of crude oil, recovers the heat of condensate, saves steam usage, and saves energy.

[0007] The crude oil gradient heating energy-saving system, comprising a condensate water tank, a first heat exchanger, a second heat exchanger, a cooling water tank and a crude oil conveying pipe, wherein the top inlet of the condensate water tank is provided with a gas-water separator, the gas-water separator inlet is connected with a condensate water pipe, the gas-water separator gas outlet is connected with a steam supply pipe through a high-temperature gas pipe I, and the gas-water separator liquid outlet is connected with the condensate water tank; the two ends of the crude oil conveying pipe are connected with an oil conveying pipeline and a crude oil storage tank respectively, and the crude oil conveying pipe is sequentially provided with a first preheating pipe, a first return pipe, a second preheating pipe and a second return pipe along the crude oil conveying direction, the first preheating pipe and the first return pipe are sequentially connected with the refrigerant inlet and the refrigerant outlet of the first heat exchanger respectively, and the second preheating pipe and the second return pipe are sequentially connected with the refrigerant inlet and the refrigerant outlet of the second heat exchanger respectively; the first heat exchanger heat medium inlet is connected with the condensate water tank through a hot water pipe, the first heat exchanger heat medium outlet is connected with the cooling water tank through a cooling water pipe, the second heat exchanger heat medium inlet is connected with the high-temperature gas pipe I and the steam supply pipe through a high-temperature gas pipe II respectively, and the second heat exchanger heat medium outlet is connected with the hot water pipe through a condensate pipe.

[0008] Preferably, the gas-water separator is a cyclone type gas-water separator.

[0009] Preferably, the first preheating pipe and the second preheating pipe are respectively connected with a first purging pipe and a second purging pipe in parallel.

[0010] Preferably, the crude oil storage tank is provided with a heating coil, and the heating coil is connected with the steam supply pipe through a heating pipe.

[0011] Preferably, the condensate pipe is provided with a drain valve.

[0012] Preferably, the cooling water tank is provided with a water outlet pipe, the water outlet pipe is connected with a water treatment device, and the water outlet pipe is provided with a cooling water conveying pump.

[0013] Preferably, the water treatment device comprises a filtering device.

[0014] Valves can be arranged on the pipes according to control needs, and the opening and closing of the valves can conveniently control the on-off of the materials in the corresponding pipes and adjust the flow of the materials.

[0015] Compared with the prior art, the crude oil gradient heating energy-saving system has the following beneficial effects:

[0016] 1. The crude oil conveying pipe sequentially passes through the first heat exchanger and the second heat exchanger for step-by-step heating during the conveying process, and the crude oil in the crude oil storage tank is heated to a high temperature as a whole, so that the time for heating to the dehydration temperature by the heating coil in the storage tank is shortened, the efficiency is improved, the steam usage amount for heating is reduced, and the temperature difference at each position after heating to the dehydration temperature is not too large due to the high initial temperature of the crude oil entering the storage tank, so that temperature stratification is avoided, and the crude oil settlement dehydration and desalination effect is improved.

[0017] 2、The gas-liquid separator carries out gas-liquid separation to the condensed water, high-temperature water vapor is into the steam supply pipe, high-temperature liquid enters the condensed water tank, and the high-temperature water in the condensed water tank enters the primary heat exchanger as the heat medium to carry out primary warming to the crude oil, then the crude oil enters the secondary heat exchanger to carry out secondary warming, the heat medium of the secondary heat exchanger is high-temperature water vapor separated from the condensed water and water vapor provided by the steam supply pipe, simultaneously, the condensate of the secondary heat exchanger heat medium outlet can be used as the heat medium of the primary heat exchanger;The crude oil is gradually heated to a higher temperature through two-stage gradient warming, and the gas phase and the liquid phase of the condensed water are separated and utilized for warming the crude oil respectively, water vapor is changed into cooling water after two times of heat exchange, and it is more beneficial to heat recovery and utilization. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic structural view of the crude oil gradient warming energy-saving system of the utility model;

[0019] In the drawing: 1, condensed water tank;2, primary heat exchanger;3, secondary heat exchanger;4, cooling water tank;5, crude oil delivery pipe;6, gas-water separator;7, condensed water pipe;8, high-temperature gas pipe one;9, steam supply pipe;10, primary preheating pipe;11, primary backflow pipe;12, secondary preheating pipe;13, secondary backflow pipe;14, hot water pipe;15, cooling water pipe;16, high-temperature gas pipe two;17, condensate pipe;18, primary purging pipe;19, secondary purging pipe;20, heating pipe;21, water outlet pipe;22, cooling water delivery pump;23, trap. DETAILED DESCRIPTION

[0020] The utility model will be described clearly and completely in combination with the drawings.

[0021] As Figure 1The crude oil gradient heating energy-saving system comprises a condensate water tank 1, a first heat exchanger 2, a second heat exchanger 3, a cooling water tank 4 and a crude oil conveying pipe 5. The top of the condensate water tank 1 is provided with a gas-water separator 6 which is a cyclone gas-water separator. The gas-water separator 6 is connected with a condensate water pipe 7. The gas outlet of the gas-water separator 6 is connected with a high-temperature gas pipe 1 8 which is connected with a steam gas supply pipe 9. The liquid outlet of the gas-water separator 6 is connected with the condensate water tank 1. The crude oil conveying pipe 5 is connected with an oil conveying pipeline and a crude oil storage tank at two ends respectively. The crude oil conveying pipe 5 is provided with a first preheating pipe 10, a first backflow pipe 1 1, a second preheating pipe 12 and a second backflow pipe 13 in sequence along the crude oil conveying direction. The first preheating pipe 10 and the first backflow pipe 1 1 are connected with the refrigerant inlet and the refrigerant outlet of the first heat exchanger 2 in sequence respectively. The second preheating pipe 12 and the second backflow pipe 13 are connected with the refrigerant inlet and the refrigerant outlet of the second heat exchanger 3 in sequence respectively. The refrigerant inlet of the first heat exchanger 2 is connected with the condensate water tank 1 through a hot water pipe 14. The refrigerant outlet of the first heat exchanger 2 is connected with the cooling water tank 4 through a cooling water pipe 15. The refrigerant inlet of the second heat exchanger 3 is connected with the high-temperature gas pipe 1 8 and the steam gas supply pipe 9 through a high-temperature gas pipe 2 16 respectively. The refrigerant outlet of the second heat exchanger 3 is connected with the hot water pipe 14 through a condensate pipe 17.

[0022] The first preheating pipe 10 and the second preheating pipe 12 are respectively connected with a first purging pipe 1 8 and a second purging pipe 19 in parallel.

[0023] The crude oil storage tank is provided with a heating coil which is connected with the steam gas supply pipe 9 through a heating pipe 20.

[0024] The condensate pipe 17 is provided with a drain valve 23.

[0025] The cooling water tank 4 is provided with a water outlet pipe 21 which is connected with a water treatment device. The water outlet pipe 21 is provided with a cooling water conveying pump 22. The water treatment device comprises a filtering device.

[0026] The working process is as follows: the crude oil in the crude oil conveying pipe enters the first heat exchanger 2 through the first preheating pipe 10 and is heated, then flows into the second preheating pipe 12 from the first backflow pipe 1 1, and is further heated in the second heat exchanger 3, and finally flows out to the crude oil storage tank through the second backflow pipe 13.

[0027] The condensate water generated by the storage tank steam heater, the crude oil reverse heating heater and the heavy oil pipeline heat tracing pipeline enters the gas-water separator 6 through the condensate water pipe 7. The high-temperature liquid enters the condensate water tank 1 through the liquid outlet of the gas-water separator 6. The high-temperature water in the condensate water tank 1 enters the first heat exchanger 2 through the hot water pipe 14 as a heat source to heat the crude oil. The high-temperature water after heat exchange becomes cooling water which enters the cooling water tank 4 through the cooling water pipe 15.

[0028] The water vapor from the outlet of the gas-water separator 6 is guided through the high-temperature gas pipe 8 and the water vapor supply pipe 9 into the high-temperature gas pipe 16 and into the secondary heat exchanger 3 as a heat source to further heat the crude oil. The water vapor after heat exchange is condensed into hot water and guided through the condensed liquid pipe 17 into the hot water pipe and into the primary heat exchanger 2 as a heat source together with the high-temperature water in the condensed water tank 1. Through two times of heat exchange, the heat in the water vapor is fully absorbed.

[0029] The cooling water in the cooling water tank 4 is treated through filtering and other processes and can be reused, thereby saving water resources.

Claims

1. A crude oil gradient heating energy-saving system, characterized in that, The system includes a condensate tank (1), a primary heat exchanger (2), a secondary heat exchanger (3), a cooling water tank (4), and a crude oil delivery pipe (5). The condensate tank (1) has a gas-liquid separator (6) at its top inlet. The inlet of the gas-liquid separator (6) is connected to a condensate pipe (7). The outlet of the gas-liquid separator (6) is connected to a steam supply pipe (9) via a high-temperature gas pipe (8). The outlet of the gas-liquid separator (6) is connected to the condensate tank (1). The crude oil delivery pipe (5) has oil pipelines and crude oil storage tanks connected at both ends. Along the crude oil delivery direction, the crude oil delivery pipe (5) is sequentially equipped with a primary preheating pipe (10), a primary return pipe (11), a secondary preheating pipe (12), and a secondary return pipe (13). The first-stage preheating pipe (10) and the first-stage return pipe (11) are connected to the refrigerant inlet and refrigerant outlet of the first-stage heat exchanger (2) in sequence, respectively. The second-stage preheating pipe (12) and the second-stage return pipe (13) are connected to the refrigerant inlet and refrigerant outlet of the second-stage heat exchanger (3) in sequence, respectively. The heat medium inlet of the first-stage heat exchanger (2) is connected to the condensate tank (1) through the hot water pipe (14). The heat medium outlet of the first-stage heat exchanger (2) is connected to the cooling water tank (4) through the cooling water pipe (15). The heat medium inlet of the second-stage heat exchanger (3) is connected to the high-temperature gas pipe (8) and the steam supply pipe (9) through the high-temperature gas pipe (2) (16) in sequence. The heat medium outlet of the second-stage heat exchanger (3) is connected to the hot water pipe (14) through the condensate pipe (17).

2. The crude oil gradient heating energy-saving system according to claim 1, characterized in that, The gas-water separator (6) is a cyclone gas-water separator.

3. The crude oil gradient heating energy-saving system according to claim 1, characterized in that, A primary purge pipe (18) and a secondary purge pipe (19) are connected in parallel on the primary preheating pipe (10) and the secondary preheating pipe (12), respectively.

4. The crude oil gradient heating energy-saving system according to claim 1, characterized in that, The crude oil storage tank is equipped with a heating coil, which is connected to a steam supply pipe (9) via a heating pipe (20).

5. The crude oil gradient heating energy-saving system according to claim 1, characterized in that, A drain valve (23) is provided on the condensate pipe (17).

6. The crude oil gradient heating energy-saving system according to claim 1, characterized in that, The cooling water tank (4) is equipped with a water outlet pipe (21), which is connected to a water treatment device. A cooling water delivery pump (22) is installed on the water outlet pipe (21).

7. The crude oil gradient heating energy-saving system according to claim 6, characterized in that, Water treatment equipment includes filtration devices.

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