阅读说明：本技术 一种油气分离回收系统及回收方法 (Oil-gas separation and recovery system and recovery method ) 是由 陈叶青 吕林梅 赵强 汪剑辉 邱鸿 郭利平 陈经 于 2020-06-11 设计创作，主要内容包括：本发明介绍了一种油气分离回收系统及回收方法,油气分离回收系统包括制冷系统和回收系统；所述的制冷系统由初级制冷剂回路和次级制冷剂回路通过一个蒸发冷凝器复叠构成,制冷系统包括初级压缩机、冷凝器、储液罐、蒸发冷凝器、预冷器、次级压缩机、回热器和深冷器；所述的回收系统包括吸收塔、汽油或柴油罐、吸附/解吸罐,真空泵和缓冲罐；该油气分离回收系统结构简单,采用“吸收/冷凝/吸附”的方法,使用一个蒸发冷凝器复叠式提供预冷和深冷所需的冷量对油气进行冷凝,再利用吸附、解吸的方法以汽油/柴油作为吸收剂分离油气中的轻烃组分,实现油气回收循环反复的不停止工作,保证油气分离回收系统可稳定、连续地运行。(The invention introduces an oil-gas separation and recovery system and a recovery method, wherein the oil-gas separation and recovery system comprises a refrigeration system and a recovery system; the refrigerating system is formed by overlapping a primary refrigerant loop and a secondary refrigerant loop through an evaporative condenser, and comprises a primary compressor, a condenser, a liquid storage tank, the evaporative condenser, a precooler, a secondary compressor, a heat regenerator and a deep cooler; the recovery system comprises an absorption tower, a gasoline or diesel tank, an adsorption/desorption tank, a vacuum pump and a buffer tank; the oil-gas separation and recovery system is simple in structure, adopts an absorption/condensation/adsorption method, uses an evaporative condenser to cascade-provide cold energy required by precooling and deep cooling to condense oil gas, and then uses gasoline/diesel oil as an absorbent to separate light hydrocarbon components in the oil gas by utilizing an adsorption and desorption method, so that the repeated non-stop work of oil-gas recovery circulation is realized, and the stable and continuous operation of the oil-gas separation and recovery system is ensured.)

1. The utility model provides an oil-gas separation recovery system, includes refrigerating system and recovery system, characterized by: the refrigerating system comprises a primary compressor (1), a condenser (2), a liquid storage tank I (3), an evaporative condenser (8), a precooler (34), a secondary compressor (9), a liquid storage tank II (10), a heat regenerator (11) and a deep cooler (13); the primary compressor (1), the condenser (2) and the liquid storage tank I (3) are sequentially connected; the evaporative condenser (8), the precooler (34) and the liquid storage tank I (3) are mutually connected, and the precooler (34) is connected with the primary compressor (1); an electric valve I (4) and an expansion valve I (5) are arranged between the liquid storage tank I (3) and the precooler (34), and an electric valve II (6) and an expansion valve II (7) are arranged between the liquid storage tank I (3) and the evaporative condenser (8); the primary compressor (1), the condenser (2), the liquid storage tank I (3), the evaporative condenser (8) and the precooler (34) form a primary refrigerant loop of the refrigeration system; the secondary compressor (9), the evaporative condenser (8), the liquid storage tank II (10), the heat regenerator (11) and the deep cooler (13) are connected in sequence; an expansion valve III (12) is arranged between the heat regenerator (11) and the deep cooler (13); the secondary compressor (9), the evaporative condenser (8), the liquid storage tank II (10), the heat regenerator (11) and the deep cooler (13) form a secondary refrigerant loop of the refrigeration system;

the recovery system comprises an absorption tower (31), a gasoline or diesel tank (27), an adsorption/desorption tank I (19), an adsorption/desorption tank II (20), a vacuum pump (18) and a buffer tank (17); the absorption tower (31) is connected with a gasoline or diesel tank (27), and the absorption tower (31) is connected with a precooler (34) of the primary refrigerant circuit; the adsorption/desorption tank I (19) and the adsorption/desorption tank II (20) are connected together and are connected with a precooler (34) and a vacuum pump (18); the vacuum pump (18) and the buffer tank (17) and the chiller (13) of the secondary refrigerant circuit are connected to each other; the absorption tower (31), the gasoline or diesel tank (27), the adsorption/desorption tank I (19), the adsorption/desorption tank II (20), the vacuum pump (18), the buffer tank (17), a precooler (34) of the refrigeration system and the deep cooler (13) form an oil-gas loop of the recovery system.

2. The oil-gas separation and recovery system according to claim 1, wherein: and an electric valve I (4) and an expansion valve I (5) between the liquid storage tank I (3) and the precooler (34), and an electric valve II (6) and an expansion valve II (7) between the liquid storage tank I (3) and the evaporative condenser (8) are connected with the PLC.

3. The oil-gas separation and recovery system and the recovery method according to claim 1, wherein the recovery system comprises: the oil gas inlet of precooler (34) and absorption/desorption jar I (19), absorption/desorption jar II (20) be equipped with stop valve I (21) respectively, stop valve II (22), stop valve III (23), stop valve IV (24), the bottom oil gas exit of absorption/desorption jar I (19) and absorption/desorption jar II (20) is provided with stop valve V (25), stop valve VI (26) respectively, stop valve V (25) and stop valve VI (26) are connected with the oil gas exit of outside, absorption/desorption jar I (19) and absorption/desorption jar II (20) are connected with vacuum pump (18) through stop valve I (21), stop valve III (23) respectively.

4. The oil-gas separation and recovery system according to claim 1, wherein: the gasoline/diesel tank (27) is connected with the top end of the absorption tower (31) through an oil supply pump (30), and the gasoline/diesel tank (27) is connected with the bottom end of the absorption tower (31) through an oil return pump (29); the top of absorption tower (31) be equipped with shower (33), the below of shower (33) is equipped with packing layer (32), absorption tower (31) bottom is equipped with liquid level transmitter (28) of the liquid level height of monitoring petrol/diesel tank (27), liquid level transmitter (28) and fuel feed pump (30) and time scavenge pump (29) all are connected with the PLC controller.

5. The oil-gas separation and recovery system according to claim 1, wherein: oil gas return circuit's buffer tank (17) and secondary refrigerant return circuit's deep freezer (13) between be equipped with solenoid valve I (14) and be used for measuring deep freezer (13) internal pressure's pressure transmitter I (35), be equipped with solenoid valve II (16) between buffer tank (17) and vacuum pump (18) and be used for measuring buffer tank (17) internal pressure's pressure transmitter II (15), solenoid valve I (14), solenoid valve II (16), pressure transmitter I (35), pressure transmitter II (15) all are connected with the PLC controller, pressure transmitter I (35) link to each other with deep freezer (13) and solenoid valve I (14) through the PLC controller, pressure transmitter II (15) link to each other with buffer tank (17) and solenoid valve II (16) through the PLC controller.

6. The oil-gas separation and recovery system according to claim 4, wherein: and adsorbent activated carbon is arranged in the adsorption/desorption tank I (19) and the adsorption/desorption tank II (20), and a concentration measuring instrument I (36) and a concentration measuring instrument II (37) for measuring the concentration of oil gas are respectively arranged on inlet and outlet pipelines of the adsorption/desorption tank I and the adsorption/desorption tank II.

7. The oil-gas separation and recovery system according to claim 4, wherein: the precooler (34) and the deep cooler (13) are both shell-and-tube heat exchangers, and the bottoms of the shell-and-tube heat exchangers are both provided with recovery outlets externally connected with condensed oil.

8. The oil-gas separation and recovery system according to claim 1, wherein: the heat regenerator (11) is provided with a first inlet (A), a first outlet (A '), a second inlet (B) and a second outlet (B '), and an expansion valve III (12) arranged between the first outlet (A ') and the deep cooler (13) is connected with the PLC.

9. The oil-gas separation and recovery system according to claim 1, wherein: the condenser (2) is an air-cooled condenser.

10. A recovery method of the oil-gas separation recovery system as set forth in any one of claims 1 to 9, characterized in that: the recovery method of the oil-gas separation recovery system adopts an absorption/condensation/adsorption method, a cascade refrigeration system of an evaporative condenser is used for dividing a refrigerant loop into two stages, precooling and deep cooling required temperatures are provided for condensing and recovering oil gas, gasoline or diesel oil is used as an absorbent for primarily absorbing hydrocarbon components of the oil gas, then the oil gas is condensed, and light hydrocarbon components in the oil gas are separated by an adsorption and desorption method for separating and recovering the oil gas; the method specifically comprises the following steps:

a. the working process of the refrigeration system is as follows:

a 1: the refrigerant in the primary compressor (1) is compressed into high-temperature and high-pressure gas, then the gas and air are subjected to partition wall heat exchange in the condenser (2), the gas is cooled and condensed into high-pressure and normal-temperature liquid, part of the liquid is left in the liquid storage tank I (3), the rest liquid is divided into two paths, and is changed into low-temperature and low-pressure gas-liquid two-phase fluid through the pressure reduction and throttling action of an electric valve and an expansion valve, wherein one path of low-temperature fluid enters the precooler (34) to provide cold energy for condensing the oil gas, the other path of low-temperature fluid enters the evaporative condenser (8) to provide cold energy for condensing the high-temperature and high-pressure refrigerant discharged by the secondary compressor (9) into liquid, the two paths of low-temperature fluid flow in the shells of the precooler (34) and the evaporative condenser (8), and the low-temperature fluid is changed into superheated vapor after absorbing the heat of the medium in the tubes and then enters the primary compressor (1) to complete the circulation of a primary refrigerant loop;

a 2: refrigerant in the secondary compressor (9) is compressed into high-temperature and high-pressure gas, the gas is discharged and then exchanges heat with the refrigerant of the primary compressor (1) in the pipe in the shell of the evaporative condenser (8), the liquid part obtained by condensation is remained in the liquid storage tank II (10), the rest refrigerant liquid enters the heat regenerator (11), enters from the first inlet (A) and the first outlet (A '), exchanges heat with the low-temperature refrigerant which is discharged from the second inlet (B) and the second outlet (B'), and goes to the air inlet of the secondary compressor (9), the refrigerant liquid discharged from the heat regenerator (11) is further cooled, is changed into low-temperature and low-pressure gas-liquid two-phase fluid after the pressure reduction and throttling action of the expansion valve III (12), enters the pipe of the deep cooler (13) to exchange heat with oil gas in the shell, the low-temperature refrigerant absorbs the heat of the oil gas, is gasified and then returns to the heat regenerator (11), the refrigerant enters from the second inlet (B) and exits from the second outlet (B'), exchanges heat with the refrigerant liquid from the liquid storage tank II (10), the gasified refrigerant is further heated, and finally enters into the secondary compressor (9) to complete the circulation of a secondary refrigerant loop;

b. the recovery system comprises the following working processes:

b 1: after external oil gas enters an absorption tower (31), a PLC controller controls an oil supply pump (30) to be started, gasoline/diesel oil from a gasoline/diesel oil tank (27) is sent to a spray pipe (33) through the oil supply pump (30), the sprayed gasoline/diesel oil is fully contacted with the external oil gas flowing upwards in a packing layer (32), part of hydrocarbon components are absorbed by the diesel oil and then fall to the bottom end of the absorption tower (31) through the packing layer (32), when the oil content in the bottom of the absorption tower (31) is high, the oil components are discharged back to the gasoline/diesel oil tank (27), the rest oil gas enters a precooler (34), moisture, dimethylbenzene and heavy hydrocarbon components in the oil gas are condensed in the shell of the precooler (34) and flow out from a condensed oil recovery outlet and are recovered, at the moment, a stop valve II (22), a stop valve III (23) and a stop valve V (25) are opened, and the stop valve I (21), Closing a stop valve IV (24) and a stop valve VI (26), allowing the rest oil gas to enter an adsorption/desorption tank I (19), and adsorbing the oil gas by the adsorption/desorption tank I (19); when the PLC monitors that the adsorption/desorption tank I (19) is saturated in adsorption, the stop valve II (22), the stop valve III (23) and the stop valve V (25) are controlled to be closed, the stop valve I (21), the stop valve IV (24) and the stop valve VI (25) are opened, the vacuum pump (18) is started to desorb the adsorption/desorption tank I (19), and at the moment, the adsorption/desorption tank II (20) adsorbs; when the adsorption/desorption tank II (20) is saturated, the working modes of the adsorption/desorption tank I (19) and the adsorption/desorption tank II (20) are changed, so that the oil-gas loop is circulated repeatedly;

b 2: when desorption is carried out, a vacuum pump (18) provides a certain vacuum degree for an adsorption/desorption tank I (19) or an adsorption/desorption tank II (20), desorbed high-purity oil gas is divided into two paths, one path of oil gas enters a shell of a deep cooler (13), the oil gas is condensed when being cooled by a refrigerant in a pipe, the other path of oil gas enters a buffer tank (17) through a solenoid valve II (16), and a PLC (programmable logic controller) controls the on-off of the solenoid valve I (14) and the solenoid valve II (16) according to pressure signals of a pressure transmitter I (35) and a pressure transmitter II (15) which are connected with the deep cooler (13) and the buffer tank (17) so as to control the replenishment amount of the buffer tank (17); the pressure transmitter I (35) and the pressure transmitter II (15) are both provided with two pressure set values, when the pressure value of the pressure transmitter II (15) is lower than the lowest value, the electromagnetic valve II (16) is opened, and oil gas enters the buffer tank (17); when the pressure value is higher than the maximum value, the electromagnetic valve II (16) is closed, and oil gas supply of the buffer tank (17) is stopped; when the pressure value of the pressure transmitter I (35) is lower than the minimum value, the electromagnetic valve I (14) is opened, and the oil gas in the buffer tank (17) enters the deep cooler (13); when the pressure value is higher than the maximum value, the electromagnetic valve I (14) is closed, oil gas supply of the deep cooler (13) is stopped, and finally, the residual oil gas which is not completely condensed returns to the adsorption tank again to be continuously adsorbed by the activated carbon.

Technical Field

The invention belongs to the technical field of oil gas recovery, and particularly relates to an oil gas separation and recovery system and a recovery method which use gasoline or diesel oil as an absorbent and use a cascade refrigeration system to divide the absorbent into two-stage loops.

Background

With the development of economy and industry, the consumption of fuel oil such as gasoline, diesel oil and the like is continuously and rapidly increased, the volatility of the fuel oil is strong, the fuel oil is difficult to volatilize to generate oil gas in the loading, unloading and fuel oil using processes of an oil tank area and a tank car, the oil gas is directly discharged into the atmosphere to cause environmental pollution, the volatilized oil gas needs to be collected, and the oil gas emission needs to meet the national specified standard. And the existing oil gas recovery technology is difficult to stably and continuously operate.

Disclosure of Invention

The invention aims to design an oil-gas separation and recovery system and a recovery method, the system adopts an absorption/condensation/adsorption method, a cascade refrigeration system of an evaporative condenser is used for dividing a refrigerant loop into two stages, precooling and deep cooling required temperatures are provided for condensing and recovering oil gas, gasoline or diesel oil is used as an absorbent for primarily absorbing hydrocarbon components of the oil gas, then the oil gas is condensed, and light hydrocarbon components in the oil gas are separated by an adsorption and desorption method for separating and recovering the oil gas.

The purpose of the invention can be realized by adopting the following technical scheme: an oil-gas separation recovery system and a recovery method, wherein the oil-gas separation recovery system comprises a refrigeration system and a recovery system, the refrigeration system comprises a primary compressor, a condenser, a liquid storage tank I, an evaporative condenser, a precooler, a secondary compressor, a heat regenerator, a deep cooler and a liquid storage tank II; the primary compressor, the condenser and the liquid storage tank I are sequentially connected; the evaporative condenser, the precooler and the liquid storage tank I are mutually connected, and the precooler is connected with the primary compressor; an electric valve I and an expansion valve I are arranged between the liquid storage tank I and the precooler, and an electric valve II and an expansion valve II are arranged between the liquid storage tank I and the evaporative condenser; the primary compressor, the condenser, the liquid storage tank I, the evaporative condenser and the precooler form a primary refrigerant loop of the refrigeration system; the secondary compressor, the evaporative condenser, the liquid storage tank II, the heat regenerator and the deep cooler are sequentially connected; an expansion valve is arranged between the heat regenerator and the deep cooler; the secondary compressor, the evaporative condenser, the liquid storage tank II, the heat regenerator and the deep cooler form a secondary refrigerant loop of the refrigeration system;

the recovery system comprises an absorption tower, a gasoline or diesel tank, an adsorption/desorption tank I, an adsorption/desorption tank II, a vacuum pump and a buffer tank; the absorption tower is connected with a gasoline or diesel tank and is also connected with a precooler of the primary refrigerant loop; the adsorption/desorption tank I and the adsorption/desorption tank II are connected together and are connected with a precooler and a vacuum pump; the vacuum pump and the buffer tank are mutually connected with each other and the chiller of the secondary refrigerant loop; the absorption tower, the gasoline or diesel tank, the adsorption/desorption tank I, the adsorption/desorption tank II, the vacuum pump, the buffer tank, a precooler and a deep cooler of the refrigeration system form an oil-gas loop of the recovery system.

And an electric valve I and an expansion valve I between the liquid storage tank I and the precooler, and an electric valve II and an expansion valve II between the liquid storage tank I and the evaporative condenser are connected with the PLC.

The oil gas inlets of the precooler, the adsorption/desorption tank I and the adsorption/desorption tank II are respectively provided with a stop valve I, a stop valve II, a stop valve III and a stop valve IV, the bottom oil gas outlets of the adsorption/desorption tank I and the adsorption/desorption tank II are respectively provided with a stop valve V and a stop valve VI, the stop valve V and the stop valve VI are connected with an external oil gas outlet, and the adsorption/desorption tank I and the adsorption/desorption tank II are respectively connected with a vacuum pump through the stop valve I and the stop valve III.

The gasoline/diesel tank pass through the fuel feed pump and be connected with absorption tower top, gasoline/diesel tank passes through scavenge pump and is connected with absorption tower bottom, the top of absorption tower be equipped with the shower, the shower below is equipped with the packing layer, absorption tower bottom is equipped with the liquid level changer of the liquid level height of monitoring gasoline/diesel tank, liquid level changer and fuel feed pump and scavenge pump all are connected with the PLC controller.

The deep cooler in buffer tank and the secondary refrigerant return circuit in oil gas return circuit between be equipped with solenoid valve I and be used for measuring pressure transmitter I of deep cooler internal pressure, be equipped with solenoid valve II between buffer tank and the vacuum pump and be used for measuring pressure transmitter II of buffer tank internal pressure, solenoid valve I, solenoid valve II, pressure transmitter I, pressure transmitter II all is connected with the PLC controller, pressure transmitter I links to each other with deep cooler and solenoid valve I through the PLC controller, pressure transmitter II links to each other with buffer tank and solenoid valve II through the PLC controller.

And adsorbent activated carbon is arranged in the adsorption/desorption tank I19 and the adsorption/desorption tank II 20, and a concentration measuring instrument I36 and a concentration measuring instrument II 37 for measuring the concentration of oil gas are respectively arranged on inlet and outlet pipelines of the adsorption/desorption tank I19 and the adsorption/desorption tank II 20.

The precooler and the deep cooler are both shell-and-tube heat exchangers, and the bottoms of the precooler and the deep cooler are both provided with recovery outlets externally connected with condensed oil.

The heat regenerator is provided with a first inlet, a first outlet, a second inlet and a second outlet, and an expansion valve III arranged between the first inlet and the deep cooler is connected with the PLC.

The condenser is an air-cooled condenser.

The recovery method of the oil-gas separation and recovery system comprises the following steps:

a. the working process of the refrigeration system is as follows:

the PLC controls the electric valve I, the expansion valve I, the electric valve II, the expansion valve II and the expansion valve III to be opened, and the primary compressor, the secondary compressor, the precooler, the evaporative condenser, the deep cooler and the heat regenerator enter a working state;

a 1: refrigerant in the primary compressor is compressed into high-temperature and high-pressure gas, then the high-temperature and high-pressure gas exchanges heat with air in a condenser, the high-temperature and high-pressure gas is condensed into high-pressure normal-temperature liquid by cooling the air, part of the liquid is retained in the liquid storage tank I, the rest of the liquid is divided into two paths, the two paths of the liquid are converted into low-temperature and low-pressure gas-liquid two-phase fluid through the pressure reduction and throttling action of an electric valve and an expansion valve, wherein one path of the low-temperature fluid enters a precooler to condense oil gas and provide cold energy, the other path of the low-temperature fluid enters an evaporation condenser to condense the high-temperature and high-pressure refrigerant discharged by a secondary compressor into liquid and provide cold energy, the two paths of the low-temperature fluid flow in the;

a 2: the refrigerant in the secondary compressor is compressed into high-temperature and high-pressure gas, the gas is discharged and exchanges heat with the refrigerant of the primary compressor in the pipe in the shell of the evaporative condenser, the liquid part obtained by condensation is remained in the liquid storage tank II, the rest refrigerant liquid enters the heat regenerator, enters the first inlet, is discharged from the first outlet, exchanges heat with the low-temperature refrigerant entering the second inlet and is discharged from the second outlet and going to the air inlet of the secondary compressor, the refrigerant liquid discharged from the heat regenerator is further cooled, is changed into low-temperature and low-pressure gas-liquid two-phase fluid through the pressure reduction and throttling action of the expansion valve III, enters the deep cooler pipe to exchange heat with the oil gas in the shell, the low-temperature refrigerant is gasified after absorbing the oil gas heat and returns to the heat regenerator again, is discharged from the second inlet and the second outlet, exchanges heat with the refrigerant liquid discharged from the liquid storage tank II, and the gasified, finally, the refrigerant enters a secondary compressor to complete the circulation of a secondary refrigerant loop;

b. the recovery system comprises the following working processes:

b 1: after external oil gas enters an absorption tower, a PLC controller controls an oil supply pump to be started, gasoline/diesel oil from a gasoline/diesel oil tank is conveyed to a spray pipe through an oil supply pump, the sprayed gasoline/diesel oil and the external oil gas flowing upwards are in full contact in a packing layer, part of hydrocarbon components are absorbed by the diesel oil and then fall to the bottom end of the absorption tower through the packing layer, when the oil content in the bottom of the absorption tower is high, the sprayed gasoline/diesel oil and the external oil gas are discharged back to the gasoline/diesel oil tank, the rest of the oil gas enters a precooler, moisture, xylene and heavy hydrocarbon components in the oil gas come down in a precooler shell when meeting condensation and flow out from a condensed oil recovery outlet and are recovered, at the moment, a stop valve II, a stop valve III and a stop valve V are opened, the stop valves I, IV and VI are closed, the rest of the oil gas; when the PLC monitors that the adsorption/desorption tank I is saturated in adsorption, the stop valves II, III and V are controlled to be closed, the stop valves I, IV and VI are opened, the vacuum pump is started to desorb the adsorption/desorption tank I, and the adsorption/desorption tank II adsorbs the adsorption/desorption tank I; when the adsorption/desorption tank II is saturated, the working modes of the adsorption/desorption tank I and the adsorption/desorption tank II are changed, and the oil-gas loop is repeatedly performed;

b 2: when desorption is carried out, the vacuum pump provides a certain vacuum degree for the adsorption/desorption tank I or the adsorption/desorption tank II, desorbed high-purity oil gas is divided into two paths, one path enters the shell of the deep cooler, the oil gas is condensed when being cooled by a refrigerant in the pipe, and the other path enters the buffer tank through the electromagnetic valve II; the PLC controls the opening and closing of the solenoid valve I and the solenoid valve II according to pressure signals of the pressure transmitter I and the pressure transmitter II which are connected with the deep cooler and the buffer tank, and controls the supply amount of the buffer tank; the pressure transmitter I and the pressure transmitter II both have two pressure set values, when the pressure value of the pressure transmitter II is lower than the lowest value, the electromagnetic valve II is opened, and oil gas enters the buffer tank; when the pressure value is higher than the maximum value, the electromagnetic valve II is closed, and the oil gas supply of the buffer tank is stopped; when the pressure value of the pressure transmitter I is lower than the lowest value, the electromagnetic valve I is opened, and oil gas in the buffer tank enters the deep cooler; when the pressure value is higher than the maximum value, the electromagnetic valve I is closed, oil gas supply of the deep cooler is stopped, and finally, the residual oil gas which is not completely condensed returns to the adsorption tank again to be continuously adsorbed by the activated carbon.

The invention has the beneficial effects that:

1. the oil-gas separation and recovery system adopts an absorption/precooling/adsorption method, uses gasoline/diesel oil as an absorbent to primarily absorb hydrocarbon components in oil gas, then precools the oil gas from an absorption tower, then adsorbs and separates light hydrocarbon components in the oil gas by using activated carbon in an adsorption/desorption tank, only uses a cascade refrigeration system to simultaneously provide temperatures required by precooling and deep cooling, and has a simpler system structure;

2. the refrigeration system is formed by overlapping two-stage (primary and secondary) refrigerant circuits through an evaporative condenser, the overlapping refrigeration system generates lower cryogenic temperature, a precooler of the primary refrigerant circuit is used for removing heavy hydrocarbon components and water, a deep cooler of the secondary refrigerant circuit is used for condensing and recovering light hydrocarbon oil gas desorbed from the adsorption/desorption tank, and the condensing method has good recovery effect on the desorbed high-purity oil gas;

3. a heat regenerator is arranged in the secondary refrigerant loop, so that lower cryogenic temperature and higher cold quantity can be obtained to meet the requirement of condensation recovery;

4. this clearly establishes a buffer tank behind the vacuum pump, can guarantee that deep cooler condensation recovery oil gas occasionally sufficient, stable oil gas supply, and the device can be stable, continuous, the operation of not shutting down.

Drawings

FIG. 1 is a flowchart of the operation of an embodiment of the present invention;

the labels in the figure are: 1. the system comprises a primary compressor, 2, a condenser, 3, a liquid storage tank I, 4, an electric valve I, 5, an expansion valve I, 6, an electric valve II, 7, an expansion valve II, 8, an evaporative condenser, 9, a secondary compressor, 10, a liquid storage tank II, 11, a heat regenerator, 12, an expansion valve III, 13, a deep cooler, 14, a solenoid valve I, 15, a pressure transmitter II, 16, a solenoid valve II, 17, a buffer tank, 18, a vacuum pump, 19, an adsorption/desorption tank I, 20, an adsorption/desorption tank II, 21, a stop valve I, 22, a stop valve II, 23, a stop valve III, 24, a stop valve IV, 25, a stop valve V, 26, a stop valve VI, 27, a gasoline/diesel tank, 28, a liquid level transmitter, 29, a return oil pump, 30, an oil supply pump, 31, an absorption tower, 32, a packing layer, 33, a spray pipe, 34, a precooler, a concentration measuring instrument I; 37. a concentration measuring instrument II is arranged on the upper portion of the device,

A. the first inlet, A ', the first outlet, B, the second inlet, B', the second outlet.

Detailed Description

The following detailed description of the embodiments of the present invention will be described in conjunction with the accompanying drawings, which are included for the purpose of illustration only and are not to be construed as limiting the invention, and in order to better illustrate the following embodiments, some components of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The connections described in the following examples are all by pipe connections, the primary compressor contains R22 refrigerant, the secondary compressor contains R13 refrigerant, and the temperature of the refrigerant R13 in the secondary compressor is lower than the temperature of the refrigerant R22 in the primary compressor; the heat exchange medium in the precooler is R22 refrigerant in the pipe, the oil-gas mixture in the shell, the heat exchange medium in the evaporative condenser is R22 refrigerant in the pipe, R13 refrigerant in the shell, and the heat exchange medium in the deep cooler is R13 refrigerant and oil-gas in the shell.

As shown in fig. 1, an oil-gas separation and recovery system and a recovery method thereof, the oil-gas separation and recovery system comprises a refrigeration system and a recovery system, the refrigeration system comprises a primary compressor 1, a condenser 2, a liquid storage tank I3, an evaporative condenser 8, a precooler 34, a secondary compressor 9, a liquid storage tank II 10, a heat regenerator 11 and a deep cooler 13; the primary compressor 1, the condenser 2 and the liquid storage tank I3 are sequentially connected; the evaporative condenser 8, the precooler 34 and the liquid storage tank I3 are mutually connected, and the precooler 34 is connected with the primary compressor 1; an electric valve I4 and an expansion valve I5 are arranged between the liquid storage tank I3 and the precooler 34, an electric valve II 6 and an expansion valve II 7 are arranged between the liquid storage tank I3 and the evaporative condenser 8, and the electric valve I, the expansion valve I, the electric valve II and the expansion valve II are all connected with a PLC (programmable logic controller); the condenser 2 is an air-cooled condenser; the primary compressor 1, the condenser 2, the liquid storage tank I3, the evaporative condenser 8 and the precooler 34 form a primary refrigerant loop of the refrigeration system; the secondary compressor 9, the evaporative condenser 8, the liquid storage tank II 10, the heat regenerator 11 and the deep cooler 13 are connected in sequence; the heat regenerator 11 is provided with a first inlet A, a first outlet A ', a second inlet B and a second outlet B ', an expansion valve III 12 is arranged between the first outlet A ' of the heat regenerator 11 and the deep cooler 13, and the expansion valve III 12 is connected with the PLC; the secondary compressor 9, the evaporative condenser 8, the liquid storage tank II 10, the heat regenerator 11 and the deep cooler 13 form a secondary refrigerant loop of the refrigeration system; the precooler 34 and the deep cooler 13 are both shell-and-tube heat exchangers, and the bottoms of the shell-and-tube heat exchangers are both provided with external condensed oil recovery outlets.

The recovery system comprises an absorption tower 31, a gasoline or diesel tank 27, an adsorption/desorption tank I19, an adsorption/desorption tank II 20, a vacuum pump 18 and a buffer tank 17, wherein the components, a precooler 34 of the refrigeration system and a deep cooler 13 form an oil-gas loop of the recovery system; the absorption tower 31 is connected with a precooler 34 of the primary refrigerant loop, a spray pipe 33 is arranged at the top end of the absorption tower 31, a packing layer 32 is arranged below the spray pipe 33, the packing layer 32 is a regular stainless steel packing, a liquid level transmitter 28 for monitoring the liquid level height of the gasoline/diesel tank 27 is arranged at the bottom of the absorption tower 31, and the liquid level transmitter 28, the oil return pump 29 and the oil supply pump 30 are all connected with a PLC (programmable logic controller); the gasoline/diesel tank 27 is connected with the top end of the absorption tower 31 through an oil supply pump 30, and the gasoline/diesel tank 27 is connected with the bottom end of the absorption tower 31 through an oil return pump 29; the adsorption/desorption tank I19 and the adsorption/desorption tank II 20 are connected together and are connected with the precooler 34 and the vacuum pump 18, adsorbent activated carbon is arranged in the adsorption tank/desorption tank I19 and the adsorption tank/desorption tank II 20, the inlet and outlet pipelines of the adsorption tank/desorption tank I19 and the adsorption tank/desorption tank II 20 are respectively provided with a concentration measuring instrument I36 and a concentration measuring instrument II 37 for measuring the concentration of oil gas, the oil gas inlets of the adsorption/desorption tank I19 and the adsorption/desorption tank II 20, which are connected with the precooler 34, are respectively provided with a stop valve I21, a stop valve II 22, a stop valve III 23 and a stop valve IV 24, the bottom oil gas outlets of the adsorption/desorption tank I19 and the adsorption/desorption tank II 20 are respectively provided with a stop valve V25 and a stop valve VI 26, the oil gas outlets are led into the outside through the stop valve V25 and the stop valve VI 26, the adsorption/desorption tank II 20 is connected with the vacuum pump 18 through a stop valve I21 and a stop valve III 23 respectively; the vacuum pump 18, the buffer tank 17 and the chiller 13 of the secondary refrigerant circuit are connected to each other; the deep cooler 13 of buffer tank 17 and secondary refrigerant return circuit between be equipped with solenoid valve I14 and be used for measuring pressure transmitter I35 of deep cooler 13 internal pressure, be equipped with solenoid valve II 15 and be used for measuring pressure transmitter II 15 of buffer tank 17 internal pressure between buffer tank 17 and the vacuum pump 18, solenoid valve I14, solenoid valve II 16, pressure transmitter I35, pressure transmitter II 15 all is connected with the PLC controller, pressure transmitter I35 links to each other with deep cooler 13 and solenoid valve I14 through the PLC controller, pressure transmitter II 15 links to each other with buffer tank 17 and solenoid valve II 16 through the PLC controller.

The specific working method for oil-gas separation and recovery comprises the following steps:

a. the working process of the refrigeration system is as follows:

a 1: the R22 refrigerant in the primary compressor 1 is compressed into high-temperature and high-pressure gas, then the high-temperature and high-pressure gas is subjected to partition wall heat exchange with air in the air-cooled condenser 2, the high-pressure and normal-temperature liquid is cooled and condensed into high-pressure and normal-temperature liquid, part of the liquid is retained in the liquid storage tank I3, the rest of the liquid is divided into two paths, the high-pressure and normal-temperature liquid is converted into low-temperature and low-pressure gas-liquid two-phase fluid through the pressure reduction and throttling effects of the expansion valve I5 and the expansion valve II 7, wherein one path of low-temperature fluid enters the precooler 34 to provide cold energy for condensing oil gas, and the other path of low-; the two paths of low-temperature fluid flow in the precooler 34 and the shell of the evaporative condenser 8, and the low-temperature fluid is changed into superheated steam after absorbing the heat of the medium in the tubes and enters the primary compressor 1 to complete the circulation of a primary refrigerant loop;

a 2: the R13 refrigerant in the secondary compressor 9 is compressed into high-temperature and high-pressure gas, the gas exchanges heat with the R22 refrigerant in the pipe in the shell of the evaporative condenser 8 after being discharged, the liquid part obtained by condensation is remained in the liquid storage tank II 10, the rest refrigerant liquid enters the heat regenerator 11, enters from the first inlet A and the first outlet A 'and exchanges heat with the low-temperature refrigerant which enters from the second inlet B and the second outlet B' and goes to the air inlet of the secondary compressor 9, the refrigerant liquid which comes out from the heat regenerator 11 is further cooled, the supercooling degree is increased, the refrigerant liquid is changed into low-temperature and low-pressure gas-liquid two-phase fluid after the pressure reduction and throttling action of the expansion valve III 12, enters the pipe of the cryogenic cooler 13 and exchanges heat with the oil gas in the shell, the low-temperature refrigerant is gasified after absorbing the heat of the oil gas and then enters the heat regenerator 11 again, enters from the second inlet B 'and goes out from the second outlet B' and exchanges, the vaporized refrigerant is further heated and finally enters the secondary compressor 9 to complete the circulation of the secondary refrigerant circuit.

b. The recovery system comprises the following working processes:

b 1: after the external oil gas enters the absorption tower 31, the PLC controller controls the oil supply pump 30 to be started, the gasoline/diesel oil from the gasoline/diesel oil tank is sent to the spray pipe 33 through the oil supply pump 30, the sprayed gasoline/diesel oil is fully contacted with the external oil gas flowing upwards in the packing layer 32, part of hydrocarbon components are absorbed by the diesel oil and then fall to the bottom end of the absorption tower 32 through the packing layer 32, when the oil level at the bottom of the absorption tower 31 rises or falls to a certain height, the PLC controller controls the start and stop of the oil return pump 29 according to the liquid level signal of the liquid level transmitter 28, the oil at the bottom of the absorption tower 31 can return to the gasoline/diesel oil tank 27 again, the rest oil gas enters the precooler 34, the moisture, the dimethylbenzene and the heavy hydrocarbon components in the oil gas are condensed and precipitated in the shell of the precooler 34 and flow out from a condensed oil recovery outlet and are recovered, and at the, The stop valve V25 is opened, the stop valve I21, the stop valve IV 24 and the stop valve VI 26 are closed, the rest oil gas enters the adsorption/desorption tank I19, and the adsorption/desorption tank I19 is used as an adsorption tank to adsorb the oil gas; when the PLC monitors that the adsorption/desorption tank I19 is saturated in adsorption, the stop valve II 22, the stop valve III 23 and the stop valve V25 are controlled to be closed, the stop valve I21, the stop valve IV 24 and the stop valve VI 26 are opened, the vacuum pump 18 is started to desorb the adsorption/desorption tank I19, and the adsorption/desorption tank II 20 serves as an adsorption tank to adsorb oil gas; when the adsorption/desorption tank II 20 is saturated in adsorption, the working modes of the adsorption/desorption tank I19 and the adsorption/desorption tank II 20 are switched, the two adsorption tanks perform adsorption and desorption, the working modes of the adsorption/desorption tank I19 and the adsorption/desorption tank II 20 are switched by detecting concentration signals of a concentration measuring instrument I36 and a concentration measuring instrument II 37 through a PLC controller and then performing logic analysis, then send out the order to each stop valve, realize the mode switch, so the circulation of oil gas return circuit is repeated, realizes that oil gas recovery work does not stop, and oil gas separation recovery system can be stable, continuous, do not shut down the ground operation, and the light hydrocarbon component in the oil gas is adsorbed on adsorbent active carbon surface, separates out from the oil gas, and remaining non-oil component or the oil gas that contains oil concentration low passes through stop valve V25, stop valve VI 26 discharge up to standard.

b 2: when desorption is carried out, the vacuum pump 18 provides a certain vacuum degree for the adsorption/desorption tank I19 or the adsorption/desorption tank II 20, desorbed high-purity oil gas is divided into two paths, one path enters the shell of the deep cooler 13, the oil gas is condensed when being cooled by a refrigerant in the pipe, the pressure in the shell of the deep cooler 13 is obviously reduced along with the large-amount condensation of the high-purity oil gas, when the flow of the desorbed high-purity light hydrocarbon component is unstable or the desorption is finished, the normal operation of a secondary refrigeration system can be influenced, and a buffer tank 17 is used for supplying the high-purity light hydrocarbon component to ensure that the deep cooler 13 has sufficient and stable oil gas supply; the other path enters a buffer tank 17 through an electromagnetic valve II 16, and a PLC (programmable logic controller) controls the opening and closing of the electromagnetic valve II 16 and a solenoid valve I14 according to pressure signals of a pressure transmitter II 15 and a pressure transmitter I35 which are connected with the buffer tank 17 and the deep cooler 13, so that the supply amount of the buffer tank 17 is controlled; the pressure transmitter I35 gives two pressure set values (a highest V1 and a lowest V2), the pressure transmitter II 15 gives two pressure set values (a highest V3 and a lowest V4), and when the pressure value of the pressure transmitter II 15 is lower than the lowest V4, the PLC controller controls the electromagnetic valve II 16 to be opened, and oil gas enters the buffer tank 17; when the pressure value is higher than the maximum value V3, the PLC controls the electromagnetic valve II 16 to close, and the oil gas supply of the buffer tank 17 is stopped; when the pressure value of the pressure transmitter I35 is lower than the lowest value V2, the PLC controls the electromagnetic valve I14 to be opened, and the oil gas in the buffer tank 17 enters the deep cooler 13; when the pressure value is higher than the maximum value V1, the PLC controls the solenoid valve I14 to close, the oil gas supply of the deep cooler 13 is stopped, and finally, the residual oil gas which is not completely condensed returns to the adsorption tank again to be adsorbed by the activated carbon.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the technical solutions of the present invention, and are not intended to limit the specific embodiments of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention claims should be included in the protection scope of the present invention claims.