阅读说明：本技术 一种油气回收装置及其预冷和保冷方法 (Oil gas recovery device and precooling and cold insulation method thereof ) 是由 温伟根 许一成 程江 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种油气回收装置,包括油气进口、风机、油气冷凝器、尾气加热器、油气输送管路、第一排油管路、回风管路、储油罐以及控制系统；所述油气进口、风机、油气冷凝器与尾气加热器通过油气输送管路依次连接；所述油气冷凝器通过第一排油管路与储油罐连接；所述尾气加热器通过回风管路与风机连接；位于风机入口处的油气输送管路上设有流量计或压力变送器,风机和尾气加热器之间的回风管路上设有回风量调节装置；所述风机、油气冷凝器、尾气加热器、流量计、压力变送器以及回风量调节装置分别与控制系统电性连接。该油气回收装置解决了油气回收装置不停机运行时,因油气量小而出现的热负荷不足的问题,并可在开机前对装置进行预冷。(The invention discloses an oil gas recovery device, which comprises an oil gas inlet, a fan, an oil gas condenser, a tail gas heater, an oil gas conveying pipeline, a first oil discharge pipeline, a return air pipeline, an oil storage tank and a control system, wherein the oil gas inlet is communicated with the oil gas condenser; the oil gas inlet, the fan, the oil gas condenser and the tail gas heater are sequentially connected through an oil gas conveying pipeline; the oil-gas condenser is connected with the oil storage tank through a first oil discharge pipeline; the tail gas heater is connected with the fan through a return air pipeline; a flow meter or a pressure transmitter is arranged on an oil gas conveying pipeline positioned at the inlet of the fan, and a return air pipeline between the fan and the tail gas heater is provided with a return air quantity regulating device; the fan, the oil-gas condenser, the tail gas heater, the flowmeter, the pressure transmitter and the return air quantity adjusting device are respectively electrically connected with the control system. The oil gas recovery device solves the problem that the oil gas recovery device is insufficient in heat load due to small oil gas amount when the oil gas recovery device does not stop running, and can be precooled before starting.)

1. An oil gas recovery device is characterized by comprising an oil gas inlet, a fan, an oil gas condenser, a tail gas heater, an oil gas conveying pipeline, a first oil discharge pipeline, a return air pipeline, an oil storage tank and a control system; the oil gas inlet, the fan, the oil gas condenser and the tail gas heater are sequentially connected through an oil gas conveying pipeline; the oil-gas condenser is connected with the oil storage tank through a first oil discharge pipeline; the tail gas heater is connected with the fan through a return air pipeline; a flow meter or a pressure transmitter is arranged on an oil gas conveying pipeline positioned at the inlet of the fan, and a return air pipeline between the fan and the tail gas heater is provided with a return air quantity regulating device; the fan, the oil-gas condenser, the tail gas heater, the flowmeter, the pressure transmitter and the return air quantity adjusting device are respectively electrically connected with the control system.

2. The oil and gas recovery device according to claim 1, wherein the oil and gas condenser comprises a first-stage oil and gas condenser, a second-stage oil and gas condenser and a third-stage oil and gas condenser which are sequentially connected through an oil and gas conveying pipeline; the first-stage oil-gas condenser is connected with the fan through an oil-gas conveying pipeline, and the third-stage oil-gas condenser is connected with the tail gas heater through an oil-gas conveying pipeline.

3. The oil and gas recovery device according to claim 2, wherein two sets of the second-stage oil and gas condenser and the three-stage oil and gas condenser are respectively arranged, and the two sets of the second-stage oil and gas condenser are respectively connected with the three-stage oil and gas condenser and then are arranged in parallel.

4. The oil and gas recovery device according to claim 2, wherein an electromagnetic valve is arranged on the oil and gas transmission pipeline between the three-stage condenser and the tail gas heater, the input end of the electromagnetic valve is connected with the three-stage condenser, and the output end of the electromagnetic valve is connected with the tail gas heater.

5. The oil and gas recovery device according to claim 1, wherein the tail gas heater is connected with a second oil discharge pipeline, and the output end of the second oil discharge pipeline is connected with the oil storage tank.

6. The oil and gas recovery device according to claim 1, wherein the air return volume adjusting device is an air volume adjusting valve or an induced draft fan.

7. A method of precooling and keeping cold for the oil and gas recovery device according to claim 1, comprising the steps of:

s01, pre-cooling starting time is set in the control system in advance according to the oil gas recovery processing requirement;

s02, when the real time reaches the set precooling starting time, the control system controls the fan, the condenser unit and the tail gas heater to be started simultaneously, the air quantity led back to the fan is adjusted to be maximum by the air return quantity adjusting device, and the oil gas recovery device starts precooling;

and S03, treating the oil gas after precooling is finished, monitoring the air volume entering the fan or the pressure at the inlet of the fan in real time by the flowmeter or the pressure transmitter, feeding the monitoring result back to the control system, controlling the return air volume adjusting device by the control system according to the monitoring result, leading the tail gas heater back to the air volume of the fan for adjusting, and enabling the air volume entering the fan to meet the requirements that the oil gas recovery device does not stop running and the oil gas recovery device keeps a cold field.

8. The pre-cooling and cold-keeping method for oil gas recovery device according to claim 7, wherein when the air volume entering the blower is monitored in real time by a flow meter and the air volume led back to the blower by the tail gas heater is adjusted, the step S03 includes the following steps:

(1) inputting an oil gas recovery device into a control system in advance to operate without stopping and meeting the minimum circulating air flow value required by the operation of a fan under the minimum frequency;

(2) the flow meter monitors the air volume entering the fan in real time, and feeds the monitoring result back to the control system to compare with the set minimum circulating air volume value:

when the flow meter monitors that the air volume value entering the fan is smaller than the minimum circulating air volume value, the control system controls the air return volume adjusting device to increase the air volume led back to the fan by the air return volume adjusting device, improve the air volume flowing back to the fan by the tail gas heater and increase the air volume entering the fan to be the same as the minimum circulating air volume value; when the flow meter monitors that the air volume value entering the fan is larger than the minimum circulating air volume value, the control system controls the air return adjusting device to reduce the air volume led back to the fan by the air return adjusting device, reduce the air volume flowing back to the fan by the tail gas heater and reduce the air volume entering the fan to be the same as the minimum circulating air volume value.

9. The pre-cooling and cold-keeping method for oil and gas recovery device according to claim 7, wherein when the pressure at the inlet of the blower is monitored in real time by the pressure transmitter and the amount of air introduced back to the blower by the tail gas heater is adjusted, the step S03 includes the following steps:

(1) inputting an oil gas recovery device into a control system in advance to operate without stopping and meeting a fan inlet pressure value corresponding to the air quantity required by the operation of a fan under the minimum frequency;

(2) the pressure transmitter monitors the pressure of the fan inlet in real time, and feeds a monitoring result back to the control system to compare with the set pressure value of the fan inlet:

when the pressure transmitter monitors that the pressure value of the fan inlet is smaller than the pressure value of the fan inlet, the control system controls the air return regulating device to increase the air quantity led back to the fan by the air return regulating device, so that the air quantity returned back to the fan by the tail gas heater is increased, and the pressure of the fan inlet is increased to be the same as the pressure value of the fan inlet; when the pressure transmitter monitors that the pressure value of the fan inlet is larger than the minimum pressure value, the control system controls the air return regulating device, so that the air quantity led back to the fan by the air return regulating device is reduced, the air quantity flowing back to the fan by the tail gas heater is reduced, and the pressure of the fan inlet is reduced to be the same as the pressure value of the fan inlet.

Technical Field

The invention relates to the technical field of oil gas recovery devices, in particular to an oil gas recovery device and a precooling and cold insulation method thereof.

Background

The oil gas recovery device can carry out condensation treatment on oil gas (mixture of gasoline and air) generated by loading and unloading of an oil tank truck or breathing of an oil tank in a tank area through the oil gas recovery device, so that the gasoline and the air are separated, and meanwhile, the gasoline is recycled and the gas meeting the emission standard is discharged to the atmosphere. Whether in a loading and unloading vehicle or a tank field, the problem that the oil gas quantity entering the oil gas recovery device is changed greatly exists, and the change of the oil gas quantity is not regular and can be circulated. The refrigeration equipment of the oil gas recovery device, such as an oil gas condenser, has large heat capacity, and long time is needed for establishing a cold field after the shutdown, and the refrigeration equipment can absorb a large amount of cold energy in the period, so that the oil gas can not be fully cooled, and the separation effect is not ideal, so that the cold field is maintained by generally adopting a non-shutdown operation mode at present. In order to keep the refrigeration equipment running without stopping under the condition of small oil and gas quantity, namely, small load on the evaporation side of the evaporator, a hot gas bypass mode is generally adopted to provide virtual load, namely, the partial exhaust volume of the compressor, namely the partial exhaust volume of the compressor bypasses the inlet of the evaporator, is mixed with the refrigerant after the expansion valve, enters the evaporator and returns to the compressor, but because the bypass flux of hot gas is difficult to be accurately controlled, the problems of overhigh exhaust temperature of the compressor, built-in protection or oil shortage fault of the compressor and the like are easy to occur, and when the oil gas volume is zero, namely the evaporation side has no load, the unit can not continue to operate in a hot gas bypass mode, at the moment, the unit can not pre-cool the equipment in advance before oil gas treatment is started, and the unit can start refrigeration operation only by introducing the oil gas, namely the evaporation side generates the load, so that the problem that the oil gas can not be fully cooled in the process of establishing a cold field occurs.

It is seen that improvements and enhancements to the prior art are needed.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide an oil gas recovery device and a precooling and cold insulation method thereof, and aims to solve the problems that when the oil gas recovery device does not stop running, the heat load is insufficient due to small oil gas amount and the prior oil gas recovery device cannot precool oil gas in advance before processing the oil gas.

An oil gas recovery device comprises an oil gas inlet, a fan, an oil gas condenser, a tail gas heater, an oil gas conveying pipeline, a first oil discharge pipeline, a return air pipeline, an oil storage tank and a control system; the oil gas inlet, the fan, the oil gas condenser and the tail gas heater are sequentially connected through an oil gas conveying pipeline; the oil-gas condenser is connected with the oil storage tank through a first oil discharge pipeline; the tail gas heater is connected with the fan through a return air pipeline; a flow meter or a pressure transmitter is arranged on an oil gas conveying pipeline positioned at the inlet of the fan, and a return air pipeline between the fan and the tail gas heater is provided with a return air quantity regulating device; the fan, the oil-gas condenser, the tail gas heater, the flowmeter, the pressure transmitter and the return air quantity adjusting device are respectively electrically connected with the control system.

In the oil gas recovery device, the oil gas condenser comprises a first-stage oil gas condenser, a second-stage oil gas condenser and a third-stage oil gas condenser which are sequentially connected through an oil gas conveying pipeline; the first-stage oil-gas condenser is connected with the fan through an oil-gas conveying pipeline, and the third-stage oil-gas condenser is connected with the tail gas heater through an oil-gas conveying pipeline.

In the oil gas recovery device, the second-stage oil gas condenser and the third-stage oil gas condenser are respectively provided with two groups, and the two groups of second-stage oil gas condensers are connected with the third-stage oil gas condenser respectively and then are arranged in parallel.

In the oil gas recovery device, an electromagnetic valve is arranged on an oil gas conveying pipeline between the three-stage condenser and the tail gas heater, the input end of the electromagnetic valve is connected with the three-stage condenser, and the output end of the electromagnetic valve is connected with the tail gas heater.

In the oil gas recovery device, the tail gas heater is connected with a second oil discharge pipeline, and the output end of the second oil discharge pipeline is connected with an oil storage tank.

In the oil gas recovery device, the air return regulating device is an air volume regulating valve or an induced draft fan.

The invention also provides a precooling and cold insulation method of the oil gas recovery device, wherein the method comprises the following steps:

s01, pre-cooling starting time is set in the control system in advance according to the oil gas recovery processing requirement;

s02, when the real time reaches the set precooling starting time, the control system controls the fan, the condenser unit and the tail gas heater to be started simultaneously, the air quantity led back to the fan is adjusted to be maximum by the air return quantity adjusting device, and the oil gas recovery device starts precooling;

and S03, treating the oil gas after precooling is finished, monitoring the air volume entering the fan or the pressure at the inlet of the fan in real time by the flowmeter or the pressure transmitter, feeding the monitoring result back to the control system, controlling the return air volume adjusting device by the control system according to the monitoring result, leading the tail gas heater back to the air volume of the fan for adjusting, and enabling the air volume entering the fan to meet the requirements that the oil gas recovery device does not stop running and the oil gas recovery device keeps a cold field.

In the pre-cooling and cold-keeping method of the oil gas recovery device, when the air volume entering the fan is monitored in real time through the flow meter and the air volume led back to the fan by the tail gas heater is adjusted, the step S03 includes the following steps:

(1) inputting an oil gas recovery device into a control system in advance to operate without stopping and meeting the minimum circulating air flow value required by the operation of a fan under the minimum frequency;

(2) the flow meter monitors the air volume entering the fan in real time, and feeds the monitoring result back to the control system to compare with the set minimum circulating air volume value:

when the flow meter monitors that the air volume value entering the fan is smaller than the minimum circulating air volume value, the control system controls the air return volume adjusting device to increase the air volume led back to the fan by the air return volume adjusting device, improve the air volume flowing back to the fan by the tail gas heater and increase the air volume entering the fan to be the same as the minimum circulating air volume value; when the flow meter monitors that the air volume value entering the fan is larger than the minimum circulating air volume value, the control system controls the air return adjusting device to reduce the air volume led back to the fan by the air return adjusting device, reduce the air volume flowing back to the fan by the tail gas heater and reduce the air volume entering the fan to be the same as the minimum circulating air volume value.

In the pre-cooling and cold-keeping method of the oil gas recovery device, when the pressure at the inlet of the fan is monitored in real time by the pressure transmitter and the air quantity led back to the fan by the tail gas heater is adjusted, the step S03 includes the following steps:

(1) inputting an oil gas recovery device into a control system in advance to operate without stopping and meeting a fan inlet pressure value corresponding to the air quantity required by the operation of a fan under the minimum frequency;

(2) the pressure transmitter monitors the pressure of the fan inlet in real time, and feeds a monitoring result back to the control system to compare with the set pressure value of the fan inlet:

when the pressure transmitter monitors that the pressure value of the fan inlet is smaller than the pressure value of the fan inlet, the control system controls the air return regulating device to increase the air quantity led back to the fan by the air return regulating device, so that the air quantity returned back to the fan by the tail gas heater is increased, and the pressure of the fan inlet is increased to be the same as the pressure value of the fan inlet; when the pressure transmitter monitors that the pressure value of the fan inlet is larger than the minimum pressure value, the control system controls the air return regulating device, so that the air quantity led back to the fan by the air return regulating device is reduced, the air quantity flowing back to the fan by the tail gas heater is reduced, and the pressure of the fan inlet is reduced to be the same as the pressure value of the fan inlet.

Has the advantages that:

the invention provides an oil gas recovery device, which is characterized in that a fan, an oil gas condenser and a tail gas heater in the device are connected in series in a circulating manner through the connection of an oil gas conveying pipeline and an air return pipeline. When carrying out oil gas treatment, the air in the oil gas is after by oil gas condenser cooling, by the heating of tail gas heater, and lead back to the calorific capacity that can also pass through fan and absorption fan motor behind the fan when tail gas heater exhaust tail gas heaies up once more, thereby guarantee that gas can constantly circulate and flow in oil gas recovery device, can also constantly provide heat load for oil gas recovery device simultaneously, so that oil gas recovery device keeps the non-stop operation, can accomplish cold-keeping for a long time, solved the non-stop operation of oil gas recovery device, because of the not enough problem of heat load that oil gas volume fluctuation appears for a short time.

The invention also provides a precooling and cold insulation method of the oil gas recovery device, which can ensure that the air quantity entering the fan and the oil gas recovery device always meets the requirements of maintaining the device to operate without stop and the fan to operate at least at the minimum frequency by means of the air return quantity regulating device arranged on the air return pipeline and the flowmeter or the pressure transmitter arranged on the oil gas conveying pipeline connected with the fan inlet. In addition, the oil gas recovery device can be automatically started in advance before oil gas treatment, so that gas in the oil gas recovery device circularly flows to precool the device.

Drawings

Fig. 1 is a schematic structural diagram of an oil gas recovery device provided by the invention.

Fig. 2 is a schematic structural diagram of an oil gas recovery device provided by the invention.

Fig. 3 is a flow chart of precooling and cold insulation of the oil gas recovery device provided by the invention.

Fig. 4 is a flowchart illustrating a specific implementation of step S03 in fig. 3.

Fig. 5 is a flowchart illustrating a specific implementation of step S03 in fig. 3 in another embodiment.

Description of the main element symbols:

1-oil gas inlet; 2-a fan; 3-first-stage oil gas condenser; 4-a secondary oil gas condenser; 5-three-stage oil gas condenser; 6-tail gas heater; 7-oil gas conveying pipeline; 8-a first oil drain line; 9-return air pipeline; 10-an oil storage tank; 11-flow meters or pressure transmitters; 12-a return air regulating device; 13-a solenoid valve; 14-second oil drain line.

Detailed Description

The invention provides an oil gas recovery device and a precooling and cold insulation method thereof, and in order to make the purpose, technical scheme and effect of the invention clearer and clearer, the invention is further described in detail by referring to the attached drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the term "connected" and the like are to be interpreted broadly, and those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific situations. Furthermore, "primary," "secondary," "tertiary," "first," and "second" are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "primary," "secondary," "tertiary," "first," and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

Referring to fig. 1, the present invention provides an oil gas recovery device, which includes an oil gas inlet 1, a blower 2, an oil gas condenser, a tail gas heater 6, an oil gas conveying pipeline 7, a first oil discharging pipeline 8, an air return pipeline 9, an oil storage tank 10, and a control system (not shown in the attached drawings); the oil gas inlet 1, the fan 2, the oil gas condenser and the tail gas heater 6 are sequentially connected through an oil gas conveying pipeline 7; the oil-gas condenser is respectively connected with an oil storage tank 10 through a first oil discharge pipeline 8; the tail gas heater 6 is connected with the fan 2 through an air return pipeline 9; a flowmeter 11 or a pressure transmitter is arranged on an oil gas conveying pipeline positioned at an inlet of the fan 2, and a return air quantity adjusting device 12 is arranged on a return air pipeline 9 between the fan 2 and the tail gas heater 6; the fan 2, the oil gas condenser, the tail gas heater 6, the flowmeter 11, the pressure transmitter and the return air regulating device 12 are respectively electrically connected with the control system.

Specifically, the air return regulating device 12 may be an air quantity regulating valve, an induced draft fan 2, or other instruments or devices having a function of regulating the magnitude of the air return.

The application provides an oil gas recovery device makes fan 2, oil gas condenser and 6 circulation series connections of tail gas heater through oil gas conveying line 7 and return air pipeline 9. When oil gas enters the fan 2, after the oil gas is cooled by the oil gas condenser, oil in the oil gas is condensed into liquid oil and is recycled to the oil storage tank 10 through the first oil discharge pipeline 8; and the air in the oil gas can be led back to the fan 2 after entering the tail gas heater 6 for heating, so that the gas in the oil gas recovery device flows circularly all the time. When the oil gas amount entering the oil gas recovery device is small or zero and further the flow meter 11 monitors that the air amount entering the fan is not small enough to enable the oil gas recovery device to operate at the minimum capacity or the fan to operate at the minimum frequency, the air amount of tail gas led back to the fan 2 is increased by controlling the air return adjusting device 12, so that the circulating air amount in the oil gas recovery device can be increased to meet the requirements that the oil gas recovery device operates without stopping and the fan 2 operates at the minimum frequency, and the oil gas recovery device operates without stopping; when the flow meter 11 monitors that the air volume entering the fan is large, the air volume of the tail gas led back to the fan 2 is reduced by controlling the air return volume adjusting device 12.

Further, this application still can adjust the tail gas amount of wind that draws back to fan 2 through the pressure of pressure transmitter real time monitoring fan entry. Specifically, when the pressure transmitter monitors that the pressure at the inlet of the fan 2 is reduced to be insufficient to enable the oil gas recovery device to operate at the minimum capacity or the fan 2 to operate at the minimum frequency, the air quantity of tail gas led back to the fan 2 is increased by controlling the air return regulating device 12, and the pressure at the inlet of the fan 2 is increased to meet the pressure requirement that the oil gas recovery device operates without stopping and the fan 2 operates at the minimum frequency; and when the pressure transmitter monitors that the pressure at the inlet of the fan is greater than the pressure requirement that the oil gas recovery device does not stop running and the fan 2 runs under the minimum frequency, the air quantity of the tail gas led back to the fan 2 is reduced by controlling the air return quantity adjusting device 12.

Compared with the prior art, this application because the air in the oil gas can be heated by tail gas heater 6 after being cooled down by oil gas condenser, draws back to fan 2 after simultaneously as tail gas heater 6 exhaust tail gas and can also heat up once more through the calorific capacity of fan 2 with the absorption fan 2 motor, therefore continuous heat load provides oil gas recovery device, so that oil gas recovery device keeps not shutting down the operation, thereby accomplishes the cold insulation for a long time.

It should be noted that the present application does not limit the form of the cooling energy source, and thus the cooling energy source of the hydrocarbon condenser may include various types such as compressor compression refrigeration.

Referring to fig. 1, while the tail gas discharged from the tail gas heater 6 is led back to the blower 2, most of the tail gas is discharged to the atmosphere after being treated by the subsequent treatment unit to reach the standard.

Further, the oil gas condenser comprises a first-stage oil gas condenser 3, a second-stage oil gas condenser 4 and a third-stage oil gas condenser 5 which are sequentially connected through an oil gas conveying pipeline 7; the first-stage oil-gas condenser 3 is connected with the fan 2 through an oil-gas conveying pipeline 7, and the third-stage oil-gas condenser 5 is connected with the tail gas heater 6 through the oil-gas conveying pipeline 7.

Because oil gas component is complicated various, contains the different light hydrocarbon component of multiple melting point and heavy hydrocarbon component simultaneously, through setting up multistage oil gas condenser, make oil gas cool down step by step, can condense heavy hydrocarbon component aftercondensation light hydrocarbon component earlier, can avoid solidifying because of the high heavy hydrocarbon component of direct cooling melting point when low temperature, and influence oil gas condenser's heat transfer effect and because of the appearance of the problem of the stifled unable oil extraction smoothly of ice.

Further, the second-stage oil-gas condenser 4 and the third-stage oil-gas condenser 5 are respectively provided with two groups, and the two groups of second-stage oil-gas condensers 4 are connected with the third-stage oil-gas condenser 5 respectively and then are arranged in parallel. Because oil gas condenser is at the in-process to oil gas condensation, can have the condition that oil gas frosted on oil gas condenser heat exchange tube all the time, continuously go on along with oil gas treatment, the condition of frosting on the heat exchange tube can be more and more heavy, finally can make oil gas condenser lose the ability to oil gas condensation, therefore in this embodiment, second grade oil gas condenser 4 and tertiary oil gas condenser 5 adopt the binary channels design, when the oil gas condenser of one of them passageway is in refrigerating condition, the oil gas condenser of another passageway is in the state of defrosting, continue to handle oil gas after the oil gas condenser of the corresponding passageway that treats to be in refrigerating condition frosts, can guarantee oil gas treatment's continuity. And to the connected mode of oil gas condenser single channel, the heat exchange tube can only shut down the machine to change the frost after frosting seriously, leads to oil gas recovery unit can't open and handle oil gas.

Further, an electromagnetic valve 13 is arranged on the oil gas conveying pipeline 7 between the three-stage condenser and the tail gas heater 6, the input end of the electromagnetic valve 13 is connected with the three-stage condenser, and the output end of the electromagnetic valve 13 is connected with the tail gas heater 6. When the oil gas recovery device does not stop working, the electromagnetic valve 13 is kept open, so that the air after oil gas separation smoothly enters the tail gas heater 6 through the oil gas conveying pipeline 7 for heating.

Referring to fig. 2, further, the tail gas heater 6 is connected to a second oil discharge pipeline 14, and an output end of the second oil discharge pipeline 14 is connected to the oil storage tank 10. After the oil gas is cooled step by step through the oil gas condenser, the liquid oil product condensed out from the oil gas condenser can still be taken to the tail gas heater 6 by the gas flowing at high speed, and the second oil discharge pipeline 14 is arranged, so that part of oil can be recovered to the oil storage tank 10 after the gas cooled by the oil gas condenser enters the tail gas heater 6.

Referring to fig. 3 and 4, the present invention further provides a method for pre-cooling and cold insulation of the oil gas recovery device, including the following steps:

s01, pre-cooling starting time is set in the control system in advance according to the oil gas recovery processing requirement;

in the step, after the oil gas recovery device is stopped, the total precooling time and the precooling starting time of the device can be preset by the control system according to the arrangement of the oil gas treatment progress.

S02, when the real time reaches the set precooling start time, the control system controls the fan 2, the condenser unit and the tail gas heater 6 to be started simultaneously, and the air quantity led back to the fan 2 is adjusted to be maximum by the air return regulating device 12, so that the gas in the oil gas recovery device continuously and circularly flows in the device, the oil gas condenser is ensured to continuously operate, and the oil gas recovery device is precooled for a period of time;

and S03, treating the oil gas after precooling is finished, monitoring the air volume entering the fan 2 or the pressure at the inlet of the fan 2 in real time by the flowmeter 11 or the pressure transmitter, feeding the monitoring result back to the control system, controlling the air return regulating device 12 by the control system according to the monitoring result, leading the tail gas heater 6 back to the air volume of the fan 2 for regulation, and enabling the air volume entering the fan 2 to meet the requirements that the oil gas recovery device does not stop running and the oil gas recovery device keeps a cold field.

Further, when the air volume entering the fan 2 is monitored in real time through the flow meter 11 and the air volume led back to the fan 2 by the tail gas heater 6 is adjusted, the step S03 further includes the following sub-steps:

(1) determining that the oil gas recovery device does not stop running and meets the minimum circulating air quantity required by the running of the fan 2 at the minimum frequency through calculation or field verification; the minimum circulating air volume is used as a basis for controlling the return air volume and controlling the return air volume adjusting device 12, such as the opening of the air volume adjusting valve; meanwhile, inputting and storing a minimum circulating air quantity value in a control system;

(2) when oil and gas treatment is carried out, the flow meter 11 monitors the air quantity entering the fan 2 in real time, and feeds a monitoring result back to the control system to be compared with a set minimum circulation quantity value; when the flow meter 11 monitors that the air volume value entering the fan 2 is smaller than the minimum circulating air volume value, the control system controls the air return adjusting device 12 to increase the air volume led back to the fan 2 by the air return adjusting device 12, so that more air volume is led back to the inlet of the fan 2 from the outlet of the tail gas heater 6, the air volume entering the fan 2 is increased to be the same as the minimum circulating air volume value, the oil gas recovery device is enabled to have enough circulating air volume to ensure that the oil gas recovery device is not stopped, and the device always has a cold field; on the contrary, when the flow meter 11 monitors that the air volume entering the fan 2 is larger than the minimum circulating air volume value, the control system controls the air return regulating device 12 to reduce the air volume led back to the fan 2 by the air return regulating device 12, reduce the air volume flowing back to the fan 2 by the tail gas heater 6, and reduce the air volume entering the fan 2 to be the same as the minimum circulating value.

Referring to fig. 3 and 5, in another embodiment, when the pressure at the inlet of the fan 2 is monitored in real time by the pressure transmitter and the amount of air introduced back to the fan 2 by the tail gas heater 6 is adjusted, the step S03 includes the following steps:

(1) determining a fan inlet pressure value corresponding to the air quantity required by the operation of the fan under the minimum frequency without stopping the operation of the oil gas recovery device through field verification, and inputting the fan inlet pressure value into a control system in advance; the fan inlet pressure value is used as a basis for controlling the return air volume and controlling the return air volume adjusting device 12, such as the opening of an air volume adjusting valve;

(2) when carrying out oil gas processing, pressure transmitter real-time supervision fan 2 entry pressure to feedback the monitoring result in control system with the settlement fan entry pressure value carries out the comparison:

when the pressure transmitter monitors that the pressure value of the inlet of the fan 2 is smaller than the pressure value of the inlet of the fan, the control system controls the air return regulating device 12 to increase the air quantity led back to the fan 2 by the air return regulating device 12, and the pressure of the inlet of the fan 2 is increased to meet the pressure requirement that the oil gas recovery device does not stop running and the fan 2 runs under the minimum frequency, so that the oil gas recovery device has enough circulating air quantity to ensure that the oil gas recovery device does not stop running and a cold field always exists in the device; when the pressure transmitter monitors that the pressure value of the inlet of the fan 2 is greater than the pressure value of the inlet of the fan, the control system controls the air return regulating device 12 to reduce the air quantity led back to the fan 2 by the air return regulating device 12, reduce the air quantity returned back to the fan 2 by the tail gas heater 6 and reduce the pressure of the inlet of the fan 2 to be the same as the pressure value of the inlet of the fan.

In summary, the present invention provides an oil gas recovery device, which enables a fan, an oil gas condenser and a tail gas heater in the device to be connected in series in a circulating manner through the connection of an oil gas delivery pipeline and an air return pipeline. When carrying out oil gas treatment, the air in the oil gas is after by oil gas condenser cooling, by the heating of tail gas heater, and lead back to the calorific capacity that can also pass through fan and absorption fan motor behind the fan when tail gas heater exhaust tail gas heaies up once more, thereby guarantee that gas can constantly circulate and flow in oil gas recovery device, can also constantly provide heat load for oil gas recovery device simultaneously, so that oil gas recovery device keeps the non-stop operation, can accomplish cold-keeping for a long time, solved the non-stop operation of oil gas recovery device, because of the not enough problem of heat load that oil gas volume fluctuation appears for a short time. Meanwhile, the invention also provides a precooling and cold insulation method of the oil gas recovery device, and the air quantity entering the fan and the oil gas recovery device can always meet the requirement of maintaining the device to operate without stop and the fan to operate at least at the minimum frequency by means of the air return quantity regulating device arranged on the air return pipeline and the flowmeter or the pressure transmitter arranged on the oil gas conveying pipeline connected with the fan inlet. In addition, the oil gas recovery device can be automatically started in advance before oil gas treatment, so that gas in the oil gas recovery device circularly flows to precool the device.

It should be understood that equivalents and modifications of the technical solution and inventive concept thereof may occur to those skilled in the art, and all such modifications and alterations should fall within the scope of the appended claims.