Pressurizing and recycling device and method for gaseous hydrocarbon separated out through water cutting of spherical tank

Abstract

The invention belongs to the technical field of petrochemical liquefied hydrocarbon storage and transportation, and particularly discloses a spherical tank water cutting separated gaseous hydrocarbon pressurization recovery device which comprises a spherical tank and a switch valve, the bottom of the spherical tank is sequentially connected with an inlet valve, a water cutting tank, a water cutting pipeline and a flash tank, a water cutting valve is installed on the water cutting pipeline, and the output end of the water cutting pipeline extends into the flash tank; the top opening of the flash tank is connected with a recovery gas path for recovering gaseous hydrocarbon, the tail end of the recovery gas path is connected into the water cutting tank, the recovery gas path is connected with a speed limiting valve and a booster pump, and a gas path working pressure sensing control device is mounted between the booster pump and the speed limiting valve; a drainage pipeline is connected to a drainage port at the bottom of the flash tank, a drainage valve and an infusion pump are mounted on the drainage pipeline, and a drainage pipeline working pressure sensing control device is mounted between the drainage valve and the infusion pump. The pressurized recovery device for the gaseous hydrocarbon separated out by water cutting of the spherical tank can completely recover the separated gaseous hydrocarbon, reduces environmental pollution, can well recycle the separated gaseous hydrocarbon, and is small in gaseous hydrocarbon loss, energy-saving, consumption-reducing, safe and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of petrochemical liquefied hydrocarbon storage and transportation, and specifically relates to a pressurized recovery device for gaseous hydrocarbons separated out by water cutting in a spherical tank and a recovery method thereof. Background Art

[0002] In the prior art, a certain amount of water will be deposited at the bottom of the gas storage tank storing liquefied hydrocarbons. Before using the liquefied hydrocarbons, they usually need to be cut off by a water cut-off tank. However, after the cut-off water containing liquefied hydrocarbons enters a flash tank with a lower pressure, the liquefied hydrocarbons will be vaporized into gaseous hydrocarbons. Usually, the gaseous hydrocarbons precipitated inside the flash tank are generally consumed by burning them in a flare system to reduce the emission of gaseous hydrocarbons. Although this method is simple, the gaseous hydrocarbons cannot be well recycled, the loss is huge, and there are also environmental problems such as carbon emissions.

[0003] Therefore, it is urgent to develop a spherical tank gaseous hydrocarbon pressurization recovery device and a recovery method thereof that can completely recover the precipitated gaseous hydrocarbons and is safe and environmentally friendly. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art, and specifically discloses a spherical tank water cutting gaseous hydrocarbon pressurization recovery device, which can completely recover the precipitated gaseous hydrocarbons, reduce environmental pollution, and can do a good job of recycling and utilization, with low gaseous hydrocarbon loss, energy saving and consumption reduction.

[0005] In order to achieve the above technical objectives, the present invention is implemented according to the following technical solutions:

[0006] The present invention discloses a pressurized recovery device for gaseous hydrocarbons separated by water cutting in a spherical tank, comprising a spherical tank for storing liquefied hydrocarbons and a switch valve at the bottom of the spherical tank, wherein the bottom of the spherical tank is sequentially connected with an inlet valve, a water cutting tank, a water cutting pipeline, and a flash tank through a water inlet pipeline, wherein the water cutting pipeline is connected to the bottom of the water cutting tank, a water cutting valve is installed on the water cutting pipeline, an output end of the water cutting pipeline extends into the flash tank, a recovery gas path for recovering gaseous hydrocarbons is connected to the top opening of the flash tank, an end of the recovery gas path is connected to the water cutting tank, a speed limiting valve and a booster pump are connected to the recovery gas path, and a gas path working pressure sensing control device P1 is installed on the recovery gas path between the booster pump and the speed limiting valve;

[0007] A drainage pipeline is connected to the bottom drainage port of the flash tank, and a drainage valve and an infusion pump are installed on the drainage pipeline. A drainage pipeline working pressure sensing control device P2 is installed on the drainage pipeline between the drainage valve and the infusion pump.

[0008] As a further improvement of the above technology, a safety pressure detector P is installed on the recovery gas path between the upper outlet of the flash tank and the speed limiting valve.

[0009] As a further improvement of the above technology, the output end of the water cut-off pipeline extending into the flash tank is an atomizing nozzle.

[0010] As a further improvement of the above technology, a float valve is provided at the bottom water outlet of the flash tank, and the density of the float in the float valve is less than the density of water and greater than the density of the liquefied hydrocarbon.

[0011] In the present invention, the volume of the flash tank is ≤30 liters, and the capacity of the flash tank is small.

[0012] The present invention also discloses a recovery method of the above-mentioned spherical tank water-cutting gaseous hydrocarbon pressurization recovery device, which specifically comprises the following steps:

[0013] (1) First, open the switch valve at the bottom of the spherical tank and the inlet valve between the spherical tank and the water cut-off tank, and the water in the spherical tank will enter the water cut-off tank in time. At this time, the water cut-off tank will not work;

[0014] (2) Then, when the water level in the water cut tank reaches a certain height, the inlet valve is closed, the water cut valve is opened, and the water cut work begins. The pressure generated by the expansion and gasification of the liquefied hydrocarbons in the water cut tank presses the water out and enters the flash tank. At the same time, the gaseous hydrocarbons separated inside the flash tank are discharged from the top into the recovery gas path, and returned to the water cut tank after being pressurized by the booster pump; the water at the bottom of the flash tank is discharged after being pressurized by the infusion pump or discharged by gravity. The aforementioned certain height of the water level can be set by the user according to the actual needs of the site;

[0015] (3) Then, after the water in the water cut-off tank is drained to the set minimum liquid level, the water cut-off valve is automatically closed. After the water in the flash tank is drained to the minimum liquid level, the float in the flash tank falls down to close the drain outlet of the flash tank. When the pressure sensed by the working pressure sensing control device P2 of the drainage pipeline decreases and is insufficient to start the infusion pump, the infusion pump stops working; when the pressure sensed by the working pressure sensing control device P1 of the gas circuit decreases and is insufficient to start the booster pump, the booster pump stops working;

[0016] (4) Finally, the inlet valve is opened, and the gaseous hydrocarbons recovered in the water cut tank are returned to the spherical tank for storage, thus completing the complete recovery process of the gaseous hydrocarbons, and the cycle continues.

[0017] In the above step (2), when the flow rate of gaseous hydrocarbons in the recovery gas line exceeds the set speed, the speed limiting valve will automatically close, and the pressure value detected by the safety pressure detector P will increase. When it exceeds the set value, the system will automatically alarm to remind the fault state and maintenance is required. The set speed is set or adjusted by the user according to the site needs.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The device for pressurizing and recovering gaseous hydrocarbons separated from water in a spherical tank of the present invention increases the pressure of gaseous hydrocarbons in the recovery gas path by arranging a booster pump on the recovery gas path, thereby recovering the separated gaseous hydrocarbons from the flash tank with a relatively low pressure into the water-cutting tank by means of boosting pressure, and returning them to the spherical tank through the original connecting pipeline, thereby achieving the purpose of increasing efficiency, saving energy and reducing emissions;

[0020] (1) The device for pressurizing and recovering gaseous hydrocarbons by cutting water from a spherical tank of the present invention can discharge the sewage discharged from the flash tank to any place where sewage treatment can be carried out by adding an infusion pump to the drainage pipeline;

[0021] (2) The pressurized recovery device for gaseous hydrocarbons separated from water in a spherical tank of the present invention is provided with a speed limiting valve and a safety pressure detector P, thereby ensuring the safety and reliability of gaseous hydrocarbon recovery;

[0022] (3) In the present invention, the provision of the gas circuit working pressure sensing control device P1 and the drainage pipeline working pressure sensing control device P2 effectively prevents the flash tank from being evacuated to a negative pressure, prevents air from entering the flash tank and the spherical tank, and avoids causing safety hazards;

[0023] (4) The existing flash tanks are usually used to collect the water discharged from multiple water cutters into a large flash tank. Such large-capacity flash tanks can store more water and are pressure vessels. They are very expensive and must be equipped with safety valves, thermometers, pressure gauges, liquid level gauges, etc., and the piping is troublesome. In the present invention, the capacity of the flash tank is relatively small, and its volume is ≤30 liters. In this way, the water cut out each time can be discharged in time, and there is no need to store the water on site. The flash tank is a container for temporarily storing the cut water. The flash tank is not a pressure vessel and does not need to be equipped with additional auxiliary equipment such as safety valves, pressure gauges, thermometers, liquid level gauges, etc. The cost is much lower and it also meets the requirements of national standards.

[0024] (5) The booster pump and the infusion pump of the spherical tank water-cutting gaseous hydrocarbon recovery device described in the present invention can be powered by gas or other power sources, and can be changed according to different application scenarios. It has a wide range of applications and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments:

[0026] Figure 1 It is a schematic structural diagram of the spherical tank gaseous hydrocarbon pressurization recovery device described in the present invention. DETAILED DESCRIPTION

[0027] like Figure 1As shown, the device for pressurizing and recovering gaseous hydrocarbons by cutting water from a spherical tank of the present invention comprises a spherical tank 1 for storing gaseous hydrocarbons and a switch valve 2 at the bottom of the spherical tank 1. The bottom of the spherical tank 1 is sequentially connected with an inlet valve 3, a water cut tank 4, a water cut pipeline 20, and a flash tank 5 through a water inlet pipeline 10. The water cut pipeline 20 is connected to the bottom of the water cut tank 4. A water cut valve 6 is installed on the water cut pipeline 20. The output end of the water cut pipeline 20 extends into the flash tank 5. The top opening of the flash tank 5 is connected with a recovery valve 6 for recovering gaseous hydrocarbons. The air circuit 30, the end of the recovery air circuit 30 is connected to the top of the water cutting tank 4, the recovery air circuit 30 is connected with a speed limiting valve 7 and a boosting pump 8, and the recovery air circuit between the boosting pump 8 and the speed limiting valve 7 is installed with an air circuit working pressure sensing control device P1; the bottom drain port of the flash tank 5 is connected with a drainage pipeline 40, the drainage pipeline 40 is installed with a drainage valve 9 and an infusion pump 11, and the drainage pipeline between the drainage valve 9 and the infusion pump 11 is installed with a drainage pipeline working pressure sensing control device P2.

[0028] In the present invention, a safety pressure detector P is installed on the recovery gas line 30 between the upper outlet of the flash tank 5 and the speed limiting valve 7; the output end of the water cut-off pipeline 20 extending into the flash tank 5 is an atomizing nozzle 12, and the setting of the atomizing nozzle 12 accelerates the vaporization of liquefied hydrocarbons.

[0029] A float valve 13 is provided at the bottom water outlet of the flash tank 5. The density of the float in the float valve 13 is less than the density of water and greater than the density of liquefied hydrocarbon.

[0030] In the present invention, the volume of the flash tank 5 is ≤30 liters. The capacity of the flash tank 5 is small, and the water cut out each time is discharged in time and does not need to be stored on site. Therefore, the flash tank 5 does not belong to a pressure vessel, and does not need to be equipped with a safety valve, a pressure gauge, a thermometer, and a liquid level gauge. The cost is much lower and the requirements of national standards are also met.

[0031] The present invention also discloses a recovery method of the above-mentioned spherical tank water-cutting gaseous hydrocarbon pressurization recovery device, which specifically comprises the following steps (such as Figure 1 shown):

[0032] (1) First, open the switch valve 2 at the bottom of the spherical tank 1 and the inlet valve 3 between the spherical tank 1 and the water cut-off tank 4, and the water in the spherical tank 1 enters the water cut-off tank 4 in time. At this time, the water cut-off tank 4 does not work;

[0033] (2) Then, when the water level in the water cut tank 4 reaches a certain height, the inlet valve 3 is closed, the water cut valve is opened, and the water cut operation begins. The pressure generated by the expansion and gasification of the liquid hydrocarbons in the water cut tank 4 presses the water out and enters the flash tank 5. At the same time, the gaseous hydrocarbons separated inside the flash tank 5 are discharged from the top into the recovery gas path 30, and are pressurized by the booster pump 8 and return to the water cut tank 4; the water at the bottom of the flash tank 5 is pressurized by the infusion pump 11 and discharged or discharged by gravity, wherein the aforementioned certain height of the water level can be set by the user according to the actual needs of the site;

[0034] (3) Then, after the water in the water cut-off tank 4 is drained to the set minimum liquid level, the water cut-off valve 6 is automatically closed. After the water in the flash tank 5 is drained to the minimum liquid level, the float in the flash tank 5 falls down to close the drainage outlet of the flash tank 5. When the pressure sensed by the working pressure sensing control device P2 of the drainage pipeline decreases and is not enough to start the infusion pump 11, the infusion pump 11 stops working; when the pressure sensed by the working pressure sensing control device P1 of the gas circuit decreases and is not enough to start the booster pump 8, the booster pump 8 stops working;

[0035] (4) Finally, the switch valve 2 and the inlet valve 3 are opened, and the gaseous hydrocarbons recovered in the water cut tank 4 are returned to the spherical tank 1 for storage, thus completing the complete recovery process of the gaseous hydrocarbons, and the cycle continues.

[0036] In the above step (2), when the flow rate of gaseous hydrocarbons in the recovery gas circuit 30 exceeds the set speed, the speed limiting valve 7 will automatically close, and the pressure value detected by the safety pressure detector P will increase. When it exceeds the set value, the system will automatically alarm to remind the fault state and maintenance is required. The set speed is set or adjusted by the user according to the site needs.

[0037] The present invention is not limited to the above-mentioned embodiments. Any changes or modifications to the present invention do not depart from the spirit and scope of the present invention. If these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also meant to include these changes and modifications.

Claims

1. A device for pressurizing and recovering gaseous hydrocarbons by cutting water from a spherical tank, comprising a spherical tank for storing liquefied hydrocarbons and a switch valve at the bottom of the spherical tank, characterized in that: The bottom of the spherical tank is connected with an inlet valve, a water cut tank, a water cut pipeline, and a flash tank in sequence through a water inlet pipeline. The water cut pipeline is connected to the bottom of the water cut tank, a water cut valve is installed on the water cut pipeline, the output end of the water cut pipeline extends into the flash tank, the top opening of the flash tank is connected with a recovery gas path for recovering gaseous hydrocarbons, the end of the recovery gas path is connected to the water cut tank, a speed limiting valve and a booster pump are connected to the recovery gas path, and a gas path working pressure sensing control device P1 is installed on the recovery gas path between the booster pump and the speed limiting valve; A drainage pipeline is connected to the bottom drainage port of the flash tank, and a drainage valve and an infusion pump are installed on the drainage pipeline. A drainage pipeline working pressure sensing control device P2 is installed on the drainage pipeline between the drainage valve and the infusion pump.

2. The device for pressurizing and recovering gaseous hydrocarbons from water removal from a spherical tank according to claim 1 is characterized in that: A safety pressure detector P is installed on the recovery gas path between the upper outlet of the flash tank and the speed limiting valve.

3. The device for pressurizing and recovering gaseous hydrocarbons from water removal from a spherical tank according to claim 1 is characterized in that: The output end of the water cutting pipeline extending into the flash tank is an atomizing nozzle.

4. The device for pressurizing and recovering gaseous hydrocarbons from water removal from a spherical tank according to claim 1 is characterized in that: A float valve is provided at the bottom water outlet of the flash tank, and the density of the float in the float valve is less than the density of water and greater than the density of liquefied hydrocarbon.

5. The device for pressurizing and recovering gaseous hydrocarbons from water removal from a spherical tank according to claim 4 is characterized in that: The volume of the flash tank is ≤30 liters.

6. The recovery method of the device for pressurizing and recovering gaseous hydrocarbons separated from water in a spherical tank according to any one of claims 1 to 5, wherein the specific steps are: (1) First, open the switch valve at the bottom of the spherical tank and the inlet valve between the spherical tank and the water cut-off tank, and the water in the spherical tank will enter the water cut-off tank in time. At this time, the water cut-off tank will not work; (2) Then, when the water level in the water cut tank reaches a certain height, the inlet valve is closed, the water cut valve is opened, and the water cut operation begins. The pressure generated by the expansion and gasification of the liquefied hydrocarbons in the water cut tank presses the water out and enters the flash tank. At the same time, the gaseous hydrocarbons separated inside the flash tank are discharged from the top into the recovery gas path, and are pressurized by the booster pump and returned to the water cut tank. The water at the bottom of the flash tank is discharged after being pressurized by the infusion pump or discharged by gravity. The aforementioned certain height of the water level can be set by the user according to the actual needs of the site; (3) Then, after the water in the water cut-off tank is drained to the set minimum liquid level, the water cut-off valve is automatically closed. After the water in the flash tank is drained to the minimum liquid level, the float in the flash tank falls down to close the drain outlet of the flash tank. When the pressure sensed by the working pressure sensing control device P2 of the drainage pipeline decreases and is insufficient to start the infusion pump, the infusion pump stops working; when the pressure sensed by the working pressure sensing control device P1 of the gas circuit decreases and is insufficient to start the booster pump, the booster pump stops working; (4) Finally, the inlet valve is opened, and the gaseous hydrocarbons recovered in the water cut tank are returned to the spherical tank for storage, thus completing the complete recovery process of the gaseous hydrocarbons, and the cycle continues.

7. The recovery method of the gaseous hydrocarbon pressurization recovery device of the spherical tank water cutting according to claim 6 is characterized by: In the above step (2), when the flow rate of gaseous hydrocarbons in the recovery gas line exceeds the set speed, the speed limiting valve will automatically close, and the pressure value detected by the safety pressure detector P will increase. When it exceeds the set value, the system will automatically alarm to remind the fault state and maintenance is required. The set speed is set or adjusted by the user according to the site needs.

Images